Review Reports - Potassium Homeostasis and the Systemic Consequences of Intracellular Potassium Deficiency: From Molecular Mechanisms to Clinical Manifestations

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I recommend rejection. The topic is potentially interesting, but the central terminology and conceptual framework are insufficiently defined. The manuscript mentions "intracellular potassium deficiency (hypokalemia)" in the Introduction, although hypokalemia conventionally refers to reduced serum potassium and is not equivalent to intracellular potassium deficiency. The manuscript then appears to discuss intracellular or tissue potassium deficiency under the non-standard term "hypokaligistia", which is confusing. More importantly, although "hypokaligistia" is used as the conceptual core of the review, it is not clearly defined, validated, or reconstructed in light of current potassium homeostasis research.
In addition, Table 1 is poorly formatted and conceptually unclear, mixing causes, triggers, associated conditions, and mechanisms without a clear hierarchy. Overall, the manuscript requires fundamental reconceptualization and restructuring rather than ordinary revision.

Author Response

Response to Reviewer 1 Comments

Dear Reviewer,

We would like to express our sincere gratitude for your careful and insightful review of our manuscript. We highly appreciate your constructive comments and valuable suggestions, which have greatly contributed to improving the scientific quality and clarity of our paper. In response to your comments, we have thoroughly revised the manuscript. The tables have been updated, the main text has been extensively revised (all changes are highlighted in color), and the reference list has been carefully revised and updated. We believe that these modifications have significantly strengthened the manuscript. Below, we provide a detailed point-by-point response to each of your comments

Point 1: The manuscript mentions "intracellular potassium deficiency (hypokalemia)" in the Introduction, although hypokalemia conventionally refers to reduced serum potassium and is not equivalent to intracellular potassium deficiency.

Response 1: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 2: The manuscript then appears to discuss intracellular or tissue potassium deficiency under the non-standard term "hypokaligistia", which is confusing.

Response 2: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 3: More importantly, although "hypokaligistia" is used as the conceptual core of the review, it is not clearly defined, validated, or reconstructed in light of current potassium homeostasis research.

Response 3: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 4: In addition, Table 1 is poorly formatted and conceptually unclear, mixing causes, triggers, associated conditions, and mechanisms without a clear hierarchy. Overall, the manuscript requires fundamental reconceptualization and restructuring rather than ordinary revision.

Response 4: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript, entitled “Disruption of Metabolic Homeostasis in Intracellular Potassium Deficiency,” addresses a clinically relevant topic and attempts to integrate potassium physiology with metabolic, cardiovascular, neurological, gastrointestinal, and endocrine alterations. The figures are visually informative, and the broad scope could make the review useful to readers interested in electrolyte homeostasis.

However, the current version contains major conceptual, mechanistic, organizational, and referencing problems. Most importantly, the manuscript repeatedly treats hypokalemia, total-body potassium depletion, and intracellular potassium deficiency as equivalent conditions. Several causal relationships are presented as established despite limited or indirect evidence, and some clinical statements—particularly those concerning metabolic alkalosis, primary aldosteronism, gastrointestinal electrophysiology, and potassium replacement—are inaccurate or insufficiently qualified. Extensive revision and comprehensive scientific fact-checking are therefore required before the manuscript can be considered for publication.

Major Comments

Hypokalemia, total-body potassium depletion, and intracellular potassium deficiency must be clearly distinguished.

The central conceptual problem is the interchangeable use of the terms “intracellular potassium deficiency,” “potassium deficiency syndrome,” “hypokalemia,” and “hypokaligistia.” These conditions are related but not synonymous. Hypokalemia is defined by a reduced serum potassium concentration and may result either from true potassium loss or from redistribution of potassium into cells. Conversely, total-body potassium depletion may initially occur with a serum potassium concentration within the reference range.

The authors should:

Define each condition at the beginning of the manuscript.
State whether the review concerns serum hypokalemia, total-body potassium depletion, tissue potassium depletion, or all three.
Explain how “intracellular potassium deficiency” is measured or inferred in humans.
Avoid using “hypokalemia” as a synonym for intracellular deficiency.
Define and justify the uncommon term “hypokaligistia,” or preferably replace it with internationally recognized terminology.

There is also an internal contradiction in Figure 3 and Table 2: potassium “leakage” from cells is said to produce extracellular hyperkalemia, whereas the remainder of the review describes hypokalemia. The compartments, temporal sequence, and underlying clinical conditions must be resolved.

A review methodology section is required.

The abstract states that the objective is “to systematize current data,” but the manuscript does not describe how the literature was identified or selected. The authors should include a section specifying:

Databases searched.
Search dates and date range.
Search terms.
Inclusion and exclusion criteria.
Whether the article is a systematic, scoping, or narrative review.
How evidence from human studies, animal models, and cell experiments was evaluated.

At present, broad clinical conclusions are frequently derived from a small number of references, particularly Reference 5, a 1982 publication by one of the authors. Contemporary primary studies and current authoritative reviews should replace or corroborate these older sources.

The proposed “primary potassium deficiency syndrome” is insufficiently supported.

The claim that primary or “essential” potassium deficiency results from a congenital deficiency in the number or function of Na⁺/K⁺-ATPase molecules requires substantial revision. Pathogenic variants in Na⁺/K⁺-ATPase genes cause defined, often tissue-specific neurological, endocrine, renal, or cardiac phenotypes; they do not currently establish a generalized syndrome of intracellular potassium deficiency that appears under psychological or physical stress.

The statement that “52 genes associated with impaired potassium metabolism have been described” must be supported by a specific reference and accompanied by a list or appropriate classification. Table 1 should separate:

Reduced intake.
Gastrointestinal losses.
Renal losses.
Transcellular redistribution.
Drug-induced hypokalemia.
Endocrine causes.
Defined inherited channelopathies and tubulopathies.

Conditions such as psycho-emotional overload, hypokinesia, vitamin deficiencies, chronic focal infection, and generalized hypoxia should not be presented as established causes of potassium depletion without strong contemporary evidence.

Causality is overstated throughout the manuscript.

The manuscript repeatedly presents potassium deficiency as the cause of systemic inflammation, insulin resistance, mitochondrial dysfunction, anabolic resistance, organ fibrosis, and multi-organ dysfunction. In many of the cited clinical conditions, inflammation, hypoxia, endocrine disease, malnutrition, medication use, and potassium imbalance coexist. The available evidence may therefore demonstrate association, bidirectional interaction, or secondary potassium disturbance rather than direct causation.

The authors should distinguish among:

Direct experimental evidence that reduced intracellular potassium causes a particular alteration.
Associations observed in patients with hypokalemia.
Effects caused primarily by the underlying disease.
Proposed or hypothetical mechanisms.

Figure 3 should be explicitly labeled as a conceptual model. Each arrow in the proposed “vicious circle” requires appropriate evidence. Statements such as “universal pathogenetic substrate” should be replaced with more balanced wording.

The metabolic alkalosis section contains a major clinical inaccuracy.

The manuscript repeatedly characterizes hypokalemic metabolic alkalosis as inherently “chloride-resistant.” This is incorrect. Metabolic alkalosis is classified according to etiology and urine chloride concentration. Vomiting, nasogastric losses, and remote diuretic exposure commonly produce chloride-responsive alkalosis, whereas mineralocorticoid excess and some states involving ongoing renal chloride loss are typically chloride-resistant. Hypokalemia can contribute to the maintenance of alkalosis, but it does not by itself determine chloride responsiveness.

This error appears in the abstract, graphical summary, Section 7, and Table 2 and must be corrected throughout. The renal mechanisms should be rewritten to include ammoniagenesis, increased distal H⁺ secretion, altered bicarbonate handling, volume status, chloride depletion, and mineralocorticoid activity.

The insulin-secretion mechanism needs greater electrophysiological precision.

In pancreatic β-cells, increased glucose metabolism raises the ATP/ADP ratio, closes ATP-sensitive K⁺ channels, reduces K⁺ efflux, depolarizes the membrane, opens voltage-gated Ca²⁺ channels, and triggers insulin secretion. The present explanation that extracellular potassium deficiency “disrupts the electrochemical gradient required for effective depolarization” is incomplete and potentially confusing.

The authors should clearly distinguish between:

K_ATP-channel gating by intracellular nucleotides.
The effect of extracellular potassium on the K⁺ equilibrium potential.
Changes in β-cell excitability caused by hypokalemia.
Evidence linking potassium status to insulin sensitivity.

Claims concerning IRS-1 activity, GLUT4 translocation, glycolysis, and glycogen synthesis require direct mechanistic references. Several currently cited references do not appear to support these specific statements.

Several cardiovascular and gastrointestinal statements require correction.

The statement that decreased potassium causes smooth-muscle membrane depolarization is not generally correct. A reduction in extracellular potassium would ordinarily shift the K⁺ equilibrium potential in a more negative direction and tend to hyperpolarize cells, although the final response may depend on Na⁺/K⁺-ATPase activity, inward rectifier channels, and tissue-specific conductances. The authors must specify whether they refer to extracellular or intracellular potassium and provide appropriate electrophysiological evidence.

The proposed use of a therapeutic spironolactone trial to determine whether aldosterone contributes to resistant hypertension should also be removed or substantially revised. Current diagnostic pathways for primary aldosteronism rely on biochemical assessment of aldosterone and renin, usually including the aldosterone-to-renin ratio, rather than interpretation of the blood-pressure response to empiric spironolactone.

Terms such as “vegetative-vascular dystonia,” “interhemispheric pyramidal asymmetry,” “oral automatism,” and “myocardiodystrophy” are outdated, nonspecific, or uncommon in contemporary English-language medical literature. These sections should be rewritten using current neurological and cardiovascular terminology.

The diagnosis of intracellular potassium deficiency is not adequately addressed.

The manuscript states that serum potassium may not reflect tissue deficiency and refers to “functional potassium tests mentioned below,” but no such validated tests are subsequently described. The authors should provide a critical discussion of:

Limitations of serum potassium.
Urinary potassium excretion and potassium-to-creatinine ratios.
Acid–base status.
Magnesium status.
Electrocardiographic findings.
Whether erythrocyte potassium or other proposed intracellular measurements are clinically validated.

The manuscript should not imply that erythrocyte potassium is an established reference standard for tissue potassium stores without adequate evidence.

The treatment section should be rewritten for accuracy and safety.

Dietary potassium intake and treatment of established hypokalemia are different issues. A dietary target of 3500–4000 mg/day should not be presented as a general therapeutic replacement regimen for potassium deficiency. Potassium replacement depends on severity, ongoing losses, renal function, magnesium status, acid–base status, electrocardiographic abnormalities, and the route of administration.

The discussion should also warn that increased potassium intake or supplementation may be inappropriate in chronic kidney disease, impaired renal excretion, or treatment with renin–angiotensin–aldosterone system inhibitors.

The WHO guideline was published in 2012 and suggests at least 90 mmol, or approximately 3510 mg, of potassium daily for most adults; Reference 3 incorrectly lists “2026.”

Furthermore, Reference 52 concerns treatment of severe hyponatremia and does not support the estimated potassium deficit or hypokalemia-treatment recommendations in lines 409–418. It must be replaced with an appropriate source.

Figures and tables require scientific and editorial revision.

The image at the beginning of page 2 appears to be a graphical abstract but is not identified as such.
In Figure 2, the Na⁺ electrochemical gradient maintained by Na⁺/K⁺-ATPase is the direct driving force for Na⁺-coupled glucose and amino-acid transport. The caption and associated text incorrectly emphasize conversion of the K⁺ gradient into “osmotic work.”
Figure 3 presents speculative causal relationships as established mechanisms.
Table 1 combines recognized causes of potassium loss with broad and insufficiently supported clinical states.
Table 2 contains the contradiction that intracellular potassium loss causes extracellular hyperkalemia in a manuscript focused on hypokalemia.
All abbreviations should be defined in the figure and table legends.
The authors should state whether the figures are original or adapted and provide source attribution where applicable.

The reference list requires a complete audit.

Numerous references do not appear to support the statements to which they are attached. Examples include:

Reference 24, concerning chronic kidney disease risk, is cited in the discussion of β-cell insulin secretion.
References 31 and 32 concern mitochondrial bioenergetics and fatigue but are used in the acid–base discussion.
Reference 52 concerns severe hyponatremia rather than potassium replacement.
Reference 3 has an incorrect publication year.
Several entries contain incomplete author punctuation, inconsistent journal formatting, typographical errors, or nonstandard source descriptions.
Reference 5 is used to support an unusually large proportion of the manuscript’s central claims despite being more than four decades old.

Every mechanistic and clinical statement should be checked against the cited source. Contemporary primary literature should be prioritized.

Minor Comments

Section numbering is inconsistent: Section 3 is absent, the manuscript begins with Section 3.1, “Anabolic Resistance” is unnumbered, and the conclusion is labeled Section 8.
Replace “the Na⁺, K⁺ pump acts as an electrogene” with “the Na⁺/K⁺ pump is electrogenic.”
The term “aerobic glycolysis” is used ambiguously. Glycolysis and mitochondrial oxidative metabolism should be distinguished.
Numerical ranges should be formatted consistently, for example 90–95%, 5–10 mmol/day, and 3.5–5.0 mmol/L.
The reported total-body potassium values are internally inconsistent: 140–160 g does not correspond exactly to the stated 3200–3800 mmol range.
The abstract should identify the article as a narrative or systematic review and avoid making therapeutic recommendations that are not developed or supported in the text.
The conclusion should acknowledge limitations and evidence gaps rather than presenting intracellular potassium deficiency as a proven universal cause of multi-organ disease.

Recommendation

Major Revision

The subject is potentially valuable, but the manuscript is not acceptable in its current form. Publication should be reconsidered only after the authors clearly redefine the scope, add a transparent review methodology, correct the physiological and clinical inaccuracies, comprehensively reassess the references, and substantially rewrite the manuscript.

Comments on the Quality of English Language

The manuscript would benefit from thorough professional English-language editing. Although the main ideas are generally understandable, many sentences are non-idiomatic, overly long, or grammatically awkward, which sometimes obscures the intended meaning. Several expressions also appear to be direct translations and are uncommon in contemporary biomedical English, including “acts as an electrogene,” “below is presented,” “cellular de-energization,” “myocardiodystrophy,” “vegetative-vascular dystonia,” and “potassium leakage.”

The authors should revise sentence structure, article use, prepositions, punctuation, and scientific terminology throughout the manuscript. Terminology should also be standardized, particularly the use of “hypokalemia,” “intracellular potassium deficiency,” “potassium deficiency syndrome,” and “hypokaligistia.” Careful editing is needed in the abstract, section headings, figure legends, tables, and references to improve clarity, precision, and consistency.

Author Response

Response to Reviewer 2 Comments

Dear Reviewer,

Point 1: Hypokalemia, total-body potassium depletion, and intracellular potassium deficiency must be clearly distinguished.

Response 1: Several closely related but distinct concepts are frequently used interchangeably in both clinical practice and the scientific literature. Hypokalemia refers exclusively to a decrease in serum potassium concentration below the lower limit of the reference range. Total-body potassium depletion denotes a reduction in whole-body potassium stores regardless of serum potassium concentration. Intracellular potassium deficiency describes reduced potassium content within cells and tissues and may occur with either normal or decreased serum potassium levels depending on the underlying pathophysiological mechanisms [4, 7, 10-13]. Because no validated clinical method currently exists for direct measurement of intracellular potassium stores, this condition is inferred from the clinical context, potassium balance, urinary potassium excretion, associated electrolyte abnormalities, and the patient's response to potassium replacement rather than measured directly [4, 7, 11, 13].

Point 2: A review methodology section is required.

Response 2: We added it accordingly

Point 3: The proposed “primary potassium deficiency syndrome” is insufficiently supported.

Response 3: As suggested by the reviewer, we have made the corrections.

Point 4: Causality is overstated throughout the manuscript.

Response 4: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 5: The metabolic alkalosis section contains a major clinical inaccuracy.

Response 5: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 6: The insulin-secretion mechanism needs greater electrophysiological precision.

Response 6: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 7: Several cardiovascular and gastrointestinal statements require correction.

Response 7: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 8: The diagnosis of intracellular potassium deficiency is not adequately addressed.

Response 8: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 9: The treatment section should be rewritten for accuracy and safety.

Response 9: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 10: Figures and tables require scientific and editorial revision.

Response 10: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Point 11: The reference list requires a complete audit.

Response 11: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have removed the non-standard term "hypokaligistia" and replaced it with the clearer descriptive term "intracellular potassium deficiency".
The terminology has therefore been substantially improved, and the distinction from hypokalemia is now clearer. Table 1 has also been reorganized and is more coherent.

Nevertheless, several issues remain. Several mechanistic claims remain stronger than the cited evidence. In particular, the statement that potassium deficiency reduces IRS-1 phosphorylation, impairs PI3K signaling, and decreases GLUT4 translocation is not directly supported by the cited studies, which mainly address impaired insulin secretion, serum potassium, or diabetes risk. The authors should provide appropriate primary evidence. Other consequences of intracellular potassium deficiency should also be clearly distinguished from established causal effects.

The graphical abstract should be revised to reflect the multifactorial and bidirectional relationships described in the text.

In addition, please carefully check the section and subsection numbering throughout the manuscript.

Author Response

Response to Reviewer 1 Comments

Dear Reviewer,

We would like to sincerely thank you for taking the time to carefully read and review our manuscript. We truly appreciate your thoughtful comments and helpful suggestions, which have been very valuable in improving both the scientific content and the clarity of our work. We hope that the revisions we have made have further strengthened the manuscript. Below, we provide our detailed responses to each of your comments, point by point. For the reviewer's convenience, all revisions to the manuscript text have been highlighted in green to indicate changes from the previous version.

Point 1: Several mechanistic claims remain stronger than the cited evidence. In particular, the statement that potassium deficiency reduces IRS-1 phosphorylation, impairs PI3K signaling, and decreases GLUT4 translocation is not directly supported by the cited studies, which mainly address impaired insulin secretion, serum potassium, or diabetes risk. The authors should provide appropriate primary evidence. Other consequences of intracellular potassium deficiency should also be clearly distinguished from established causal effects.Response 1: Dear Reviewer, we thank you for your careful and constructive comment regarding the mechanistic claims in our manuscript. We fully agree with your observation that the original wording overstated the strength of the evidence linking intracellular potassium depletion to specific impairments in insulin signaling. In response to your comment, we have revised the relevant paragraph as follows: Original version (for reference): "Reduced phosphorylation of insulin receptor substrate-1 (IRS-1), impaired phosphatidylinositol-3 kinase signaling, and decreased translocation of glucose transporter type 4 (GLUT4) have been demonstrated primarily in experimental models [14, 22, 24, 25]." Revised version (now in the manuscript): "Based on extrapolation from related experimental models, potassium deficiency has been suggested to reduce IRS-1 phosphorylation, impair PI3K signaling, and decrease GLUT4 translocation [14, 22, 24, 25]. However, direct evidence specifically attributing this complete molecular cascade to potassium depletion remains limited, and these putative mechanisms should be viewed as potential contributing pathways rather than established causal effects in vivo."

And

Original version (for reference): “In addition to impaired insulin signaling, intracellular potassium deficiency may reduce glycogen synthesis, suppress oxidative glucose metabolism, and decrease exercise tolerance by limiting ATP production within skeletal muscle. Mitochondrial dysfunction and oxidative stress further amplify these metabolic disturbances, emphasizing the close interaction among potassium homeostasis, cellular bioenergetics, and insulin sensitivity”

Revised version (now in the manuscript): In addition to possible alterations in insulin signaling, experimental studies suggest that potassium depletion may influence glycogen synthesis, oxidative glucose metabolism, and skeletal muscle bioenergetics. Mitochondrial dysfunction and oxidative stress have also been proposed as potential mediators, although direct evidence supporting these mechanisms in humans remains limited [13, 25, 31].

Point 2: The graphical abstract should be revised to reflect the multifactorial and bidirectional relationships described in the text.Response 2: We are very grateful to the reviewer for this valuable comment. We fully agree that the graphical abstract should adequately reflect the multifactorial and bidirectional nature of the described relationships. At the same time, since we have decided at this stage to remove the graphical abstract from the text of the article, it seemed more logical to us not to revise it, but to omit it from the manuscript, so as not to inadvertently oversimplify the data presented in the work.

Point 3: In addition, please carefully check the section and subsection numbering throughout the manuscript.

Response 3: We are grateful to the reviewer for drawing our attention to this point. Indeed, there were inaccuracies in the numbering of sections and subsections. We have carefully double-checked the entire manuscript and corrected the numbering in all relevant places.

1. Introduction

2. Methods

3. Potassium Metabolism in Humans

4. Physiological Role of Potassium

5. Potassium deficiency syndrome

5.1. Systemic inflammation,

5.2. Insulin Resistance and Glucose Metabolism

5.3. Mitochondrial Dysfunction

5.4. Metabolic Alkalosis

5.5. Anabolic Resistance

6. Clinical Manifestations

7. Principles of diagnosis

8. Principles of management and correction of hypokalemia

9. Conclusions

Reviewer 2 Report

Comments and Suggestions for Authors

The revised manuscript has improved compared with the previous version, and several of the major conceptual concerns appear to have been addressed. In particular, the distinction among hypokalemia, total-body potassium depletion, and intracellular potassium deficiency has been clarified, and the authors now appropriately acknowledge that intracellular potassium deficiency cannot currently be measured directly by a validated routine clinical method.

However, the revision still requires additional clarification and editorial improvement before acceptance. The point-by-point response is too generic for many of the previous major comments. Except for the first point, most responses simply state that “the corrections have been made,” without indicating where the changes were introduced, what text was modified, which references were added or removed, or how the figures and tables were revised. The authors should provide a more informative response letter indicating the specific manuscript sections, figures, tables, or references that were modified in response to each comment.

The manuscript should also be checked carefully to ensure that the distinction among serum hypokalemia, total-body potassium depletion, and intracellular potassium deficiency is maintained consistently throughout the abstract, introduction, figures, tables, clinical sections, and conclusions. These terms should not be used interchangeably. If the term “hypokaligistia” is retained, it should be clearly defined and justified, because it is not commonly used in contemporary English-language biomedical literature.

The section on metabolic alkalosis should be verified again. The manuscript should not imply that hypokalemic metabolic alkalosis is inherently chloride-resistant. Chloride-responsive and chloride-resistant metabolic alkalosis should be distinguished according to etiology, volume status, urinary chloride concentration, and mineralocorticoid activity.

The revised manuscript should continue to avoid overstating causality. Potassium deficiency may contribute to systemic inflammation, insulin resistance, mitochondrial dysfunction, acid–base disturbances, anabolic resistance, and organ dysfunction, but many of these relationships are bidirectional, context-dependent, or based on associative evidence. The authors should clearly distinguish established mechanisms from proposed hypotheses or clinical associations.

The insulin-secretion section should maintain electrophysiological precision. In pancreatic β-cells, glucose metabolism increases the ATP/ADP ratio, closes ATP-sensitive K⁺ channels, reduces K⁺ efflux, depolarizes the membrane, opens voltage-gated Ca²⁺ channels, and triggers insulin secretion. Any discussion of hypokalemia or altered potassium gradients should be integrated into this mechanism carefully and supported by appropriate references.

The cardiovascular and gastrointestinal sections should be reviewed again for mechanistic accuracy and contemporary clinical terminology. Outdated or nonspecific terms such as “myocardiodystrophy,” “vegetative-vascular dystonia,” and related expressions should be avoided or replaced with terminology that is commonly used in current biomedical literature.

The diagnostic section should continue to emphasize that intracellular potassium deficiency cannot currently be diagnosed directly in routine clinical practice. The authors should avoid implying that serum potassium, erythrocyte potassium, or functional potassium tests provide a validated direct measurement of tissue potassium stores unless strong evidence is provided.

The therapeutic section should remain clinically cautious. Dietary potassium intake should not be conflated with therapeutic replacement of established hypokalemia. Potassium replacement should be individualized according to severity, renal function, ongoing losses, acid–base status, magnesium status, ECG findings, route of administration, and risk of hyperkalemia.

The figures and tables should be checked for scientific accuracy, readability, abbreviation definitions, and source attribution. Figure 3 should be presented as a conceptual model rather than as a proven causal pathway unless each connection is directly supported by evidence.

Finally, the reference list should undergo a final comprehensive audit. Each citation should be checked to ensure that it directly supports the corresponding statement. Older sources, including the authors’ 1982 publication, should not be used as the main support for contemporary mechanistic or clinical claims unless corroborated by current independent literature.

Overall, the manuscript is substantially improved and may be suitable for publication after minor revisions, provided that the remaining conceptual, editorial, and bibliographic issues are carefully addressed.

Comments on the Quality of English Language

The English language has improved in the revised manuscript, and the text is generally understandable. However, additional editing is still recommended to improve clarity, precision, and consistency. Some expressions remain non-idiomatic or uncommon in contemporary biomedical English, and several sentences would benefit from simplification.

The authors should carefully revise terminology related to potassium homeostasis, including “hypokalemia,” “total-body potassium depletion,” “intracellular potassium deficiency,” and “hypokaligistia,” to ensure consistent use throughout the manuscript. Section headings, figure legends, tables, and the reference list should also be checked for grammar, punctuation, capitalization, and formatting consistency.

Author Response

Response to Reviewer 2 Comments

Dear Reviewer,

Point 1: Hypokalemia, total-body potassium depletion, and intracellular potassium deficiency must be clearly distinguished.

Response 1: We thank the reviewer for this important comment. The relevant section has been revised and is presented below:

Several closely related but distinct concepts are frequently used interchangeably in both clinical practice and the scientific literature. Hypokalemia refers exclusively to a decrease in serum potassium concentration below the lower limit of the reference range. Total-body potassium depletion denotes a reduction in whole-body potassium stores regardless of serum potassium concentration. Intracellular potassium deficiency describes reduced potassium content within cells and tissues and may occur with either normal or decreased serum potassium levels depending on the underlying pathophysiological mechanisms [4, 7, 10-13]. Because no validated clinical method currently exists for direct measurement of intracellular potassium stores, this condition is inferred from the clinical context, potassium balance, urinary potassium excretion, associated electrolyte abnormalities, and the patient's response to potassium replacement rather than measured directly [4, 7, 11, 13].

Point 2: A review methodology section is required.

Response 2: We are very grateful to the reviewer for this valuable comment. We added it accordingly

Methods

This article was prepared as a narrative review of the current literature concerning potassium homeostasis and intracellular potassium deficiency.

Literature searches were conducted using PubMed/MEDLINE, Scopus, and Google Scholar for publications available through January 2026. Search terms included combinations of potassium homeostasis, hypokalemia, potassium depletion, intracellular potassium, Na⁺/K⁺-ATPase, potassium metabolism, mitochondrial dysfunction, insulin resistance, metabolic alkalosis, and gastrointestinal motility.

Original research articles, systematic reviews, meta-analyses, clinical practice guidelines, and landmark experimental studies were considered. Greater emphasis was placed on contemporary human studies and international clinical guidelines, whereas earlier publications were included when they established fundamental physiological concepts that remain relevant to the current understanding of potassium homeostasis [4, 7, 11, 13, 15].

Because direct assessment of intracellular potassium stores is not routinely available in clinical practice and the available evidence remains heterogeneous, this review was designed as a narrative rather than a systematic review.

Regarding Reference 5 (the 1982 publication by one of the authors), we have taken the following actions: We have retained the 1982 publication solely as a historical reference to acknowledge the pioneering observations in this area. However, we have made it clear in the text that this source is cited for historical context rather than as primary evidence for contemporary mechanistic or clinical conclusions. To this end, we have revised the wording and, where appropriate, added a clarifying phrase such as:

The concept of potassium deficiency syndrome, first proposed by V. T. Ivashkin in the early 1980s, describes the multisystem functional disturbances associated with chronic potassium depletion [5]. Although this term is not used in contemporary international clinical practice, it remains valuable as a conceptual framework for understanding the systemic metabolic consequences of prolonged intracellular potassium deficiency. Throughout the present review, the term is used primarily to refer to chronic intracellular potassium depletion and total-body potassium deficiency.

Point 3: The proposed “primary potassium deficiency syndrome” is insufficiently supported.

Response 3: We thank the reviewer for this important comment. We fully agree with this point and have revised the corresponding section of the manuscript accordingly...

Potassium deficiency syndrome

Disturbances of potassium homeostasis frequently develop gradually over weeks or months and may remain clinically unrecognized until substantial depletion of intracellular and total-body potassium stores has occurred. Because serum potassium reflects only a small fraction of total-body potassium, chronic potassium depletion may exist despite serum potassium concentrations within the reference range. Consequently, the clinical consequences of potassium deficiency are determined not only by serum potassium concentration but also by the magnitude, duration, and underlying mechanism of potassium imbalance [4, 7, 11, 13, 14].

Experimental studies demonstrate that chronic potassium depletion induces adaptive cellular responses involving altered Na⁺/K⁺-ATPase activity, changes in transmembrane ion transport, activation of the renin–angiotensin–aldosterone system, increased renal ammoniagenesis, oxidative stress, and remodeling of intracellular metabolic pathways. Initially, these adaptive responses preserve extracellular potassium concentration; however, persistent compensation may occur at the expense of progressive intracellular potassium depletion and functional impairment of metabolically active tissues [13, 18, 19, 31].

Accumulating evidence further indicates that chronic potassium depletion is associated with a broad spectrum of metabolic abnormalities, including oxidative stress, mitochondrial dysfunction, systemic inflammation, insulin resistance, endothelial dysfunction, metabolic alkalosis, and impaired protein synthesis. However, these relationships are highly interconnected and frequently bidirectional. Some of the mechanisms are well characterized and firmly established, whereas others remain incompletely elucidated. Potassium deficiency should therefore be regarded as one component of an integrated pathophysiological network rather than an isolated pathogenic mechanism [13, 20-35].

The following sections discuss the principal mechanisms through which chronic potassium depletion may contribute to systemic metabolic disturbances while distinguishing well-established physiological concepts from mechanisms that remain incompletely understood.

Point 4: Causality is overstated throughout the manuscript.

Response 4: We fully agree with this point and have revised the corresponding section of the manuscript accordingly: 5. Potassium deficiency syndrome, 5.1. Systemic inflammation, 5.2. Insulin Resistance and Glucose Metabolism, 5.3. Mitochondrial Dysfunction, 5.4. Metabolic Alkalosis, 5.5. Anabolic Resistance, 6. Clinical Manifestations, 7. Principles of diagnosis, and 8. Principles of management and correction of hypokalemia.

Point 5: The section on metabolic alkalosis should be verified again. The manuscript should not imply that hypokalemic metabolic alkalosis is inherently chloride-resistant. Chloride-responsive and chloride-resistant metabolic alkalosis should be distinguished according to etiology, volume status, urinary chloride concentration, and mineralocorticoid activity.

Response 5: We thank the reviewer for this important comment. We have carefully reviewed Section 5.4, "Metabolic Alkalosis," and corrected the inaccuracy noted. The corresponding section has been revised in accordance with current clinical guidelines and physiological data. The revised text is presented below: Clinically, metabolic alkalosis is classified as either chloride-responsive or chloride-resistant based on etiology, volume status, urinary chloride concentration, and mineralocorticoid activity. This distinction is critical for guiding appropriate therapeutic management, as chloride-responsive and chloride-resistant alkalosis require fundamentally different treatment approaches.

Chloride-responsive metabolic alkalosis is typically associated with extracellular volume depletion, gastrointestinal chloride loss (e.g., vomiting, nasogastric suction), previous diuretic therapy, or other conditions accompanied by chloride and volume deficit. In these cases, urinary chloride concentration is typically low (< 20–25 mmol/L), and alkalosis generally responds to volume repletion together with chloride and potassium replacement. It is important to emphasize that most cases of hypokalemic metabolic alkalosis encountered in clinical practice belong to this category, as they arise in the setting of diuretic therapy, fluid losses, or gastrointestinal losses [15, 38].

Chloride-resistant metabolic alkalosis, by contrast, is most commonly associated with persistent mineralocorticoid excess, including primary aldosteronism, Cushing syndrome, or inherited disorders of mineralocorticoid signaling. In these patients, urinary chloride concentration is typically elevated (> 40 mmol/L), and correction of potassium deficiency alone is insufficient without addressing the underlying endocrine disorder; treatment must be directed at the underlying etiology. In clinical practice, chloride-resistant alkalosis is encountered less frequently; however, its recognition is of critical importance, as it may indicate the presence of a serious endocrine disorder [15, 38].

Point 6: The insulin-secretion section should maintain electrophysiological precision. In pancreatic β-cells, glucose metabolism increases the ATP/ADP ratio, closes ATP-sensitive K⁺ channels, reduces K⁺ efflux, depolarizes the membrane, opens voltage-gated Ca²⁺ channels, and triggers insulin secretion. Any discussion of hypokalemia or altered potassium gradients should be integrated into this mechanism carefully and supported by appropriate references.

Response 6: We thank the reviewer for this important comment. We fully agree that electrophysiological precision is essential in describing insulin secretion. In response, we have revised Section 5.2 to ensure that the complete sequence of events is accurately described. The revised text is presented below for the reviewer's consideration.

5.2. Insulin Resistance and Glucose Metabolism

Disturbances of potassium homeostasis are closely associated with abnormalities of glucose metabolism affecting both insulin secretion and peripheral insulin sensitivity. These relationships are complex and bidirectional. Potassium depletion may impair glucose homeostasis, whereas diabetes mellitus, hyperglycemia, insulin therapy, and associated endocrine disorders can themselves alter potassium distribution and increase the risk of hypokalemia. Accordingly, potassium deficiency should be viewed as one component of the broader metabolic network underlying disorders of glucose regulation rather than an isolated electrolyte disturbance [13, 22, 23-25, 30].

Normal insulin secretion depends on tightly regulated potassium fluxes within pancreatic β-cells. Under physiological conditions, glucose metabolism increases the intracellular ATP/ADP ratio, leading to closure of ATP-sensitive potassium (K_ATP) channels, reduced potassium efflux, and subsequent membrane depolarization. This depolarization subsequently opens voltage-gated calcium channels, allowing calcium influx and triggering exocytosis of insulin-containing secretory granules [13, 22, 23, 30].

Experimental and clinical studies indicate that disturbances of potassium homeostasis may alter β-cell electrophysiology and attenuate glucose-stimulated insulin secretion. Both chronic potassium depletion and acute hypokalemia appear capable of reducing insulin release, although the magnitude of this effect depends on the severity and duration of potassium deficiency and on concomitant metabolic abnormalities.

The mechanisms underlying this effect are complex and may involve altered transmembrane potassium gradients, changes in K_ATP channel conductance, or impaired β-cell membrane excitability [22, 23,25, 30]. Studies consistently demonstrate impaired glucose tolerance in patients with hypokalemia, particularly during chronic diuretic therapy or primary aldosteronism, where correction of potassium deficiency frequently improves glucose metabolism [22, 23,25, 30].

Several complementary mechanisms have been proposed to explain the relationship between intracellular potassium depletion and reduced insulin sensitivity. Experimental evidence suggests that potassium deficiency impairs skeletal muscle glucose utilization through alterations in intracellular enzyme activity, mitochondrial ATP production, and insulin signaling pathways. Based on extrapolation from related experimental models, potassium deficiency has been suggested to reduce IRS-1 phosphorylation, impair PI3K signaling, and decrease GLUT4 translocation [14, 22, 24, 25]. However, direct evidence specifically attributing this complete molecular cascade to potassium depletion remains limited, and these putative mechanisms should be viewed as potential contributing pathways rather than established causal effects in vivo.

Nevertheless, available clinical evidence indicates that potassium depletion alone is unlikely to represent an independent cause of insulin resistance. Instead, these molecular abnormalities interact with obesity, chronic inflammation, activation of the renin–angiotensin–aldosterone system, chronic kidney disease, aging, and physical inactivity to determine the overall degree of insulin resistance.

In addition to possible alterations in insulin signaling, experimental studies suggest that potassium depletion may influence glycogen synthesis, oxidative glucose metabolism, and skeletal muscle bioenergetics. Mitochondrial dysfunction and oxidative stress have also been proposed as potential mediators, although direct evidence supporting these mechanisms in humans remains limited [13, 25, 31].

Although correction of potassium deficiency has been shown to improve glucose metabolism in selected patient populations, particularly individuals receiving thiazide or loop diuretics and patients with primary aldosteronism, current evidence does not support potassium supplementation as an independent strategy for prevention or treatment of insulin resistance in the general population. Additional prospective studies are required to determine the independent metabolic effects of chronic intracellular potassium depletion [15, 36, 37, 38].

Point 7: Several cardiovascular and gastrointestinal statements require correction.

Response 7: We sincerely thank the reviewer for careful reading. As suggested by the reviewer, we have made the corrections:

- Cardiovascular manifestations are of particular clinical importance because disturbances of potassium homeostasis significantly increase the risk of cardiac arrhythmias. Typical electrocardiographic abnormalities include flattening or inversion of T waves, ST-segment depression, prominent U waves, QT interval prolongation, and increased ventricular ectopy. Patients with structural heart disease, heart failure, ischemic heart disease, or concomitant use of antiarrhythmic medications are especially susceptible to the proarrhythmic effects of hypokalemia [11,37-43]. …..

- Gastrointestinal manifestations result primarily from reduced smooth muscle contractility and include constipation, delayed gastric emptying, abdominal distension, intestinal hypomotility, and, in severe cases, paralytic ileus or intestinal pseudo-obstruction. Patients with chronic gastrointestinal diseases, hereditary tubulopathies, or prolonged diuretic therapy may be particularly vulnerable to these complications [46–48]. In addition to its role in gastrointestinal motility, K⁺ is essential for several other physiological processes, including enzyme secretion and activation, epithelial repair, and the maintenance of epithelial barrier integrity [47–50].

Point 8: The diagnostic section should continue to emphasize that intracellular potassium deficiency cannot currently be diagnosed directly in routine clinical practice. The authors should avoid implying that serum potassium, erythrocyte potassium, or functional potassium tests provide a validated direct measurement of tissue potassium stores unless strong evidence is provided.

Response 8: We thank the reviewer for this important comment. We fully agree that intracellular potassium deficiency cannot currently be diagnosed directly in routine clinical practice. In response, we have revised Section 7 to explicitly state that although various surrogate markers—including serum potassium concentration, erythrocyte potassium content, and functional potassium tests—have been proposed, none has been validated for direct measurement of intracellular or total-body potassium stores. We have also emphasized that diagnosis relies on a synthesis of clinical and laboratory findings rather than on a single direct measurement. The revised text is presented below for the reviewer's consideration:

Principles of diagnosis

Evaluation of potassium disorders should extend beyond measurement of serum potassium concentration. Although serum potassium remains the principal laboratory parameter used in clinical practice, it represents less than 2% of total-body potassium and therefore provides only limited information regarding intracellular potassium stores. Diagnosis requires integration of clinical findings, biochemical assessment, and evaluation of the underlying disease [7, 11, 13].

The initial diagnostic approach should determine whether hypokalemia results from reduced potassium intake, gastrointestinal potassium loss, renal potassium wasting, or transcellular redistribution. Clinical history should include assessment of medication use (particularly diuretics, laxatives, insulin, and β₂-adrenergic agonists), gastrointestinal symptoms, dietary habits, endocrine disorders, and family history of inherited renal tubular diseases [7, 11, 13]].

Laboratory evaluation should include serum potassium, magnesium, sodium, chloride, bicarbonate, creatinine, glucose, and assessment of acid–base status. Measurement of urinary potassium excretion is particularly useful for distinguishing renal from extrarenal potassium losses. Elevated urinary potassium excretion in the setting of hypokalemia suggests inappropriate renal potassium wasting, whereas low urinary potassium excretion indicates gastrointestinal losses or inadequate intake [7, 11, 13, 18].

Assessment of plasma renin activity and aldosterone concentration is indicated in patients with resistant hypertension, unexplained hypokalemia, metabolic alkalosis, or suspected mineralocorticoid excess. Early recognition of primary aldosteronism is especially important because targeted treatment may substantially improve cardiovascular and renal outcomes [15, 38].

Electrocardiography should be performed in patients with moderate or severe hypokalemia, symptoms suggestive of cardiac involvement, pre-existing cardiovascular disease, or use of medications that increase arrhythmic risk. ECG abnormalities support the diagnosis but do not reliably estimate the severity of total-body potassium depletion [11, 37, 42].

At present, no validated clinical biomarker accurately reflects intracellular potassium stores. Although various surrogate markers—including serum potassium concentration, erythrocyte potassium content, and functional potassium tests—have been proposed, none has been validated for direct measurement of intracellular or total-body potassium stores in routine clinical practice. Therefore, diagnosis of chronic potassium depletion relies on synthesis of clinical history, laboratory findings, acid–base status, urinary potassium excretion, associated electrolyte abnormalities, and the patient's response to potassium replacement therapy rather than on a single direct measurement [13]. Development of reliable biomarkers of intracellular potassium status remains an important area for future clinical research.

Point 9: The therapeutic section should remain clinically cautious. Dietary potassium intake should not be conflated with therapeutic replacement of established hypokalemia. Potassium replacement should be individualized according to severity, renal function, ongoing losses, acid–base status, magnesium status, ECG findings, route of administration, and risk of hyperkalemia

Response 9: We thank the reviewer for this important comment. We fully agree that dietary potassium intake should not be conflated with therapeutic replacement of established hypokalemia, and that potassium replacement must be individualized according to multiple clinical parameters. In response, we have revised Section 8 to include a dedicated statement explicitly listing the factors that should guide individualized potassium replacement: severity of hypokalemia, renal function, ongoing losses, acid–base status, magnesium status, ECG findings, route of administration, and risk of hyperkalemia. We have also emphasized that dietary modification should complement rather than replace treatment of the underlying cause. The revised text is presented below for the reviewer's consideration:

Principles of management and correction of hypokalemia

Management of potassium disorders should focus primarily on identification and correction of the underlying cause. Restoration of serum potassium concentration alone is often insufficient unless ongoing potassium losses, acid–base disturbances, endocrine abnormalities, and concomitant magnesium deficiency are simultaneously addressed [11, 13].

Potassium replacement should be individualized according to the severity of hypokalemia, renal function, ongoing losses, acid–base status, magnesium status, ECG findings, route of administration, and risk of hyperkalemia [11, 13, 15, 38].

Oral potassium supplementation is the preferred treatment for patients with mild to moderate hypokalemia who are clinically stable and able to tolerate enteral therapy. Potassium chloride is generally recommended because it simultaneously corrects potassium deficiency and chloride depletion, particularly in patients with metabolic alkalosis [11, 13].

Intravenous potassium replacement should be reserved for patients with severe hypokalemia, life-threatening arrhythmias, profound muscle weakness, inability to tolerate oral therapy, or gastrointestinal dysfunction preventing adequate absorption. Intravenous administration requires continuous electrocardiographic monitoring and frequent reassessment of serum potassium concentrations because excessively rapid correction may result in dangerous hyperkalemia [11].

Correction of hypomagnesemia is a critical component of therapy. Magnesium deficiency impairs renal potassium conservation and frequently prevents successful correction of hypokalemia. Failure to recognize concomitant magnesium depletion is a common cause of persistent or recurrent hypokalemia despite apparently adequate potassium replacement [11, 13].

Treatment should also address the underlying mechanism responsible for potassium depletion. This may include modification of diuretic therapy, treatment of gastrointestinal potassium losses, optimization of glycemic control, management of endocrine disorders such as primary aldosteronism, correction of acid–base disturbances, and treatment of chronic kidney disease when present. In patients requiring long-term diuretic therapy, potassium-sparing agents may reduce urinary potassium loss when clinically appropriate [11, 13, 15, 38].

Dietary counseling should encourage adequate intake of potassium-rich foods in patients without contraindications such as advanced chronic kidney disease or impaired renal potassium excretion. Foods particularly rich in potassium include dried fruits, legumes, potatoes, leafy green vegetables, bananas, avocados, fish, and other minimally processed foods. Nevertheless, dietary modification should complement rather than replace treatment of the underlying cause of potassium depletion [2, 13, 53, 57, 58].

Because disturbances of potassium homeostasis frequently coexist with metabolic, cardiovascular, renal, and endocrine disorders, management is often most effective when integrated into a comprehensive strategy aimed at improving overall cardiometabolic health rather than correcting serum potassium concentration alone.

Point 10: The figures and tables should be checked for scientific accuracy, readability, abbreviation definitions, and source attribution. Figure 3 should be presented as a conceptual model rather than as a proven causal pathway unless each connection is directly supported by evidence.

Response 10: We thank the reviewer for this valuable comment. We fully agree that all figures and tables should adhere to the highest standards of scientific accuracy, readability, and appropriate source attribution, and that conceptual models should not be overinterpreted as proven causal pathways.

In response to this comment, we have carefully reviewed all figures and tables in the manuscript. Specifically, we have revised Table 1 and Table 2 to ensure that all data are scientifically accurate, that abbreviations are clearly defined, and that all sources are properly attributed.

Regarding Figure 3, we have given careful consideration to the reviewer's concern. Upon re-evaluation, we recognized that the figure could potentially be misinterpreted as depicting established causal relationships rather than a conceptual framework. To avoid any such ambiguity and to maintain the highest scientific rigor, we have removed Figure 3 from the manuscript entirely. The key concepts previously illustrated in the figure are now described narratively in the text with appropriate contextualization and explicit acknowledgment of their hypothetical nature.

We believe that these revisions have improved the clarity and scientific accuracy of the manuscript. We are most grateful to the reviewer for this thoughtful suggestion.

The revised tables are presented below for the reviewer's consideration.

Table 1. Conceptual framework of disturbances of potassium homeostasis

Condition	Definition	Typical mechanisms	Laboratory findings	Potential metabolic consequences
Hypokalemia	Decreased serum potassium concentration (<3.5 mmol/L)	Renal potassium loss, gastrointestinal loss, transcellular potassium redistribution	↓ Serum K⁺; total-body potassium may be normal or decreased	Neuromuscular dysfunction, cardiac arrhythmias, impaired insulin secretion, altered acid–base balance
Total-body potassium depletion	Reduction of total body potassium stores irrespective of serum potassium concentration	Chronic inadequate intake, renal or gastrointestinal potassium loss, prolonged negative potassium balance	Serum K⁺ may be normal or decreased	Chronic potassium depletion, muscle weakness, impaired renal concentrating ability, metabolic disturbances
Intracellular potassium deficiency	Reduced intracellular potassium content despite variable serum potassium concentration	Impaired Na⁺/K⁺-ATPase activity, altered transcellular potassium distribution, chronic potassium depletion	No direct clinical biomarker; suspected from clinical context	Mitochondrial dysfunction, impaired glucose metabolism, anabolic resistance, altered inflammatory signaling

Table 2. Conceptual framework of metabolic consequences of potassium homeostasis disturbances

Mechanism	Principal pathways	Potential consequences
Systemic inflammation	Oxidative stress, altered Na⁺/K⁺-ATPase activity, possible NLRP3 inflammasome activation	Chronic low-grade inflammation, further disturbance of potassium homeostasis
Insulin resistance and impaired insulin secretion	Altered β-cell electrophysiology, impaired insulin signaling, reduced glucose utilization	Glucose intolerance, impaired insulin sensitivity
Mitochondrial dysfunction	Altered mitochondrial potassium homeostasis, impaired oxidative phosphorylation, increased ROS production	Reduced ATP synthesis, fatigue, reduced exercise tolerance
Metabolic alkalosis	Increased renal H⁺ secretion, enhanced bicarbonate reabsorption, RAAS activation	Maintenance of potassium depletion, impaired tissue oxygen delivery
Anabolic resistance	Mitochondrial dysfunction, inflammation, impaired insulin signaling, reduced anabolic response and protein synthesis	Loss of muscle mass, delayed tissue repair, reduced physical performance

Point 11: Тhe reference list should undergo a final comprehensive audit. Each citation should be checked to ensure that it directly supports the corresponding statement. Older sources, including the authors’ 1982 publication, should not be used as the main support for contemporary mechanistic or clinical claims unless corroborated by current independent literature.

Response 11: We sincerely thank the reviewer for this thoughtful and constructive comment. We fully agree that a comprehensive audit of the reference list is essential to ensure the scientific rigor and credibility of our manuscript.

In response to this comment, we have undertaken a systematic and thorough revision of the entire reference list. Each citation has been carefully re-evaluated to confirm that it directly and accurately supports the corresponding statement in the text. Wherever older sources were previously used to support contemporary mechanistic or clinical claims, we have replaced or supplemented them with current, independent, and peer-reviewed literature from the past decade, including recent primary studies and authoritative reviews.

With regard to the 1982 publication by one of the authors, we have retained this reference in the reference list exclusively as a historical reference to acknowledge the pioneering observations in this field. Given that the author of that early publication is also a co-author of the present work, we considered it both scientifically appropriate and historically accurate to preserve this citation for its historical context. However, we wish to emphasize that this source is no longer used as primary support for any contemporary mechanistic or clinical conclusions. All current claims are now substantiated by up-to-date, independent literature.

We believe that these revisions have substantially strengthened the scholarly quality and evidentiary foundation of our manuscript. We are most grateful to the reviewer for this valuable suggestion, which has significantly improved our work.