Muscles

Background: The Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) is used to assess upper-extremity performance in a closed kinetic chain position. The standard hand placement of 36 inches may favor individuals with larger body dimensions. Methods: Sixty-five healthy adults (44 males, 21 females; 18–33 years) performed the CKCUEST under two conditions: the standard position and a modified position with hand distance set at 50% of arm span. The mean number of touches, standard score, and power score were calculated for each condition. Reliability and the effects of sex and body composition were also examined. Results: Performance was significantly better in the modified position for mean touches (24.4 ± 4.47 vs. 23.0 ± 4.62, p = 0.001), standard score (0.4 ± 0.07 vs. 0.3 ± 0.06, p = 0.001), and power (81.1 ± 18.29 vs. 77.1 ± 22.00, p = 0.001). Both conditions showed excellent reliability (ICC = 0.944–0.946). Females performed significantly fewer touches than males in the standard position (p = 0.001), whereas this difference was not significant in the modified position. Several anthropometric and body composition variables significantly predicted performance. Conclusions: An arm-span-adjusted hand position improves CKCUEST performance and may provide a fairer assessment across individuals with different body dimensions. Full article

Background: Musculoskeletal pain remains a major cause of disability worldwide, encompassing disorders such as rheumatoid arthritis (RA), osteoarthritis (OA) and chronic back pain. Acupuncture and dry needling are increasingly used for symptom management, yet their effects on inflammatory modulation remain unclear. This systematic review and meta-analysis evaluated the influence of acupuncture on inflammatory biomarker regulation in musculoskeletal pain. Methods: Following PRISMA and Cochrane methodological guidelines, comprehensive searches were conducted across MEDLINE (via PubMed), Web of Science, Cochrane Library, Scopus, Google Scholar, and OpenEvidence from inception to August 2025. Eligible studies were randomized controlled trials (RCTs) involving acupuncture or dry needling interventions with inflammatory biomarker outcomes. Screening, data extraction, and risk of bias assessment using ROB2 were performed by two reviewers independently. The certainty of evidence was appraised using GRADE criteria. The protocol was registered on PROSPERO (CRD420251011831). Results: Nineteen RCTs and one randomized cross-over study (n = 1492) met inclusion criteria. Some studies demonstrated reductions in CRP, ESR, IL-1β, IL-6 and TNF-α following acupuncture. Random-effects meta-analysis indicated that modified acupuncture (electroacupuncture or needle-knife therapy) significantly reduced TNF-α in knee OA compared with traditional acupuncture (SMD = −1.63, 95% CI −2.47 to −0.80, p < 0.01) but not IL-1β. However, no significant effects were observed from acupuncture versus sham acupuncture for CRP or ESR in patients with arthritis. However, the findings are limited by high heterogeneity and the small number of studies included in each meta-analysis. Conclusions: A moderate level of GRADE evidence suggests that modified acupuncture may be more effective than standard acupuncture in reducing TNF-α levels in patients with OA. Further high-quality biomarker-based RCTs are warranted to confirm these findings. This study received no external funding. Full article

Centronuclear myopathy (CNM) is a genetically heterogenous congenital myopathy traditionally classified as a membrane remodeling disorder. Emerging evidence reveals that centronuclear myopathy mutations converge upon common cellular dysfunction extending beyond membrane trafficking. This review proposes a unified model positioning CNM as a disorder of impaired organelle communication and structural crosstalk. We focus on how mutations in Myotubularin1 (MTM1) and gain-of-function mutations in Dynamin 2 (DNM2) disrupt the triad architecture, leading to aberrant calcium handling, mitochondrial dysfunction, imbalanced reactive oxygen species (ROS) production, and defective autophagy. These dysfunctions are not isolated but form a pathological feedback loop that compromises muscle integrity and regeneration. By identifying shared mechanisms across CNM types, this review positions the disorder as the convergence of organelle stress and cytoskeletal network failure. This perspective reveals novel therapeutic strategies based on the principle that targeting a central pathological node may alleviate systemic dysfunction. However, given the complexity of the organelle feedback loop, a comprehensive, multi-target approach may ultimately be required to achieve full phenotypic rescue across all affected tissues. Full article

Background: Respiratory muscle strength (RMS) is a critical factor influencing athletic performance, particularly in high-intensity or prolonged activities. RMS encompasses inspiratory (IMs) and expiratory muscles (EMs), which differ in anatomical structure, fiber composition, and responsiveness to training. Methods: This pilot interventional within-subject study investigated the effects of two resistive respiratory muscle training (RMT) protocols on RMS and small airway function in eight physically active adults (two females, six males). Maximal inspiratory (MIP) and expiratory pressures (MEP), along with pulmonary function tests (PFTs), were measured using the Airofit PRO™ device and spirometry before and after two consecutive 7-day training protocols, with a 2-day break between interventions. The workload was progressively increased by lengthening the duration of forced inhalation and exhalation, while keeping the air resistance constant. Results: Results demonstrated significant improvements in MEP across both protocols and after a 10-day washout period (p < 0.001–0.03), whereas MIP showed no significant changes (p = 0.19–0.66). Moderate transient improvements were observed in small airway flow (MEF25%) following the first protocol (ES = 0.62), which regressed after the second. Conclusions: These outcomes suggest differential responsiveness of respiratory muscles to RMT; EMs, characterized by a higher proportion of fast-twitch type II fibers and a predominantly passive role in normal breathing, respond rapidly to short-duration, high-intensity forced expiration training through neuromuscular adaptations. Conversely, IMs, dominated by slow-twitch type I fibers, require longer-duration, higher-load training to elicit meaningful adaptations, explaining the limited changes in MIP. Small airway function appeared minimally trainable due to structural and physiological constraints, with short-term improvements likely reflecting effort-dependent factors rather than lasting adaptations. Finally, RMT can selectively enhance EM performance through appropriately designed short-duration, high-intensity interventions, while IMs may necessitate prolonged or higher-load stimuli. The findings highlight the importance of targeted training strategies, individualized to muscle fiber composition and functional demands, to optimize respiratory performance. Future research should investigate longer interventions, larger diverse cohorts, and precise measurement methods to further elucidate RMT’s effects on both respiratory muscles and small airway function. Full article

Background/Objectives: Sarcopenia, characterized by progressive loss of skeletal muscle mass and function, is a major public health concern among aging populations. While physical activity is recognized as protective, the comparative effectiveness of different exercise modalities remains understudied in Asian populations. This cross-sectional study investigated the association between exercise type and sarcopenia prevalence among Korean adults aged 40 years and older. Methods: This cross-sectional study analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2024. A total of 1688 adults aged ≥40 years were included. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia (AWGS) 2019 criteria, incorporating dual-energy X-ray absorptiometry (DXA)-based appendicular skeletal muscle mass index (ASMI) and handgrip strength. Due to the absence of physical performance measures in this survey cycle, the operational definition required both low ASMI and low handgrip strength. Exercise types were categorized into four groups: no exercise, aerobic only, resistance only, and combined exercise. Multivariable logistic regression, adjusting for age, sex, socioeconomic status, lifestyle factors, nutritional intake, and comorbidities, was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Sarcopenia prevalence was 13.2% (n = 223). In the fully adjusted model, resistance-only exercise was associated with 56% lower odds of sarcopenia (OR 0.44, 95% CI 0.23–0.82, p = 0.010), and combined exercise with 69% lower odds (OR 0.31, 95% CI 0.13–0.78, p = 0.012). Aerobic-only exercise showed no significant association (OR 0.88, 95% CI 0.54–1.42, p = 0.594). The protective association was statistically significant in the 60–69 age group (OR 0.28, 95% CI 0.11–0.74), with similar but non-significant trends in other age groups. Conclusions: Resistance exercise, either alone or combined with aerobic exercise, is associated with lower odds of sarcopenia in Korean adults aged 40 and older. These observational findings warrant further investigation through prospective and interventional studies before informing public health strategies. Interpretation should consider the limited sample size in the resistance-only subgroup (n = 18 with sarcopenia) and the cross-sectional design, which precludes causal inference. Full article

Neuromuscular electrical stimulation (NMES) is integral to studying muscle function in healthy and dystrophic mice. Certain commercial electrodes and laboratory stimulators used for NMES in mice are no longer in production. We developed and/or tested low-cost, open-source alternatives to discontinued commercial standards. We performed two studies—a comparison of electrodes and a comparison of stimulators. In the electrode study, in vivo NMES was applied to the left hindlimb ankle dorsiflexors in healthy C57BL/6J and dysferlin-null BLAJ mice using three electrode types: a previously available commercial electrode, a custom 3D-Printed electrode, and a custom Pen electrode assembled from off-the-shelf components. Twitch and tetanic torque were measured and compared using two-way repeated-measures ANOVA. Twitch torque differed by electrode type (p = 0.031), with lower values observed for the Pen electrode compared with the 3D-Printed electrode (e.g., 573 ± 72 vs. 666 ± 70 mN.mm in C57BL/6J mice), whereas tetanic torque did not differ significantly between electrode types (p = 0.060). In the stimulator study, twitch and tetanic contractions were elicited using the open-source StimJim stimulator and compared with contractions elicited by the discontinued Grass S48 stimulator. Twitch torque was lower with the StimJim (588 ± 107 mN.mm) compared with the Grass S48 (698 ± 116 mN.mm; p < 0.001), whereas tetanic torque values were not statistically different (p = 0.055). These findings indicate that open-source electrodes and stimulators can produce similar maximal tetanic torque under the tested conditions, although differences in twitch torque and stimulation parameters should be considered. These results reflect a methodological validation of accessible tools rather than a formal equivalence analysis. Full article

Stretching of the upper trapezius muscle reduces stiffness and choroidal blood flow velocity, but its effect on skin blood flow remains unclear. We evaluated the changes in upper trapezius skin circulation hemodynamics before/after self-stretching using skin laser speckle flowgraphy (LSFG). Twenty-two healthy young adults (median age [Q1–Q3]: 21.0 [20.0–21.0] years) were enrolled. Trapezius stiffness was assessed using ultrasound strain elastography, and skin and choroidal blood were measured with skin and ocular LSFG, respectively, using mean blur rate (MBR) as an index of blood flow velocity. Intraocular pressure (IOP); systolic (SBP), diastolic (DBP), and mean blood pressure (MBP); heart rate (HR); ocular perfusion pressure (OPP); salivary α-amylase (sAA) activity; and subjective eyestrain/shoulder stiffness symptoms (visual analog scale, VAS) were evaluated at baseline and after stretching. SBP, DBP, MBP, OPP, sAA activity, VAS scores for eyestrain and shoulder stiffness, trapezius stiffness, and skin and choroidal MBR decreased significantly after self-stretching, whereas IOP and HR remained unchanged. Trapezius muscle self-stretching reduces muscle stiffness and induces relaxation in healthy adults, accompanied by reduced sympathetic activity and decreased systemic, choroidal, and local skin circulation. These findings suggest that skin LSFG may serve as a useful, non-invasive tool for evaluating shoulder stiffness. Full article

Background: Tensiomyography (TMG) offers a noninvasive means of evaluating skeletal muscle contractile properties, including muscle displacement (Dm), delay time (Td), contraction time (Tc), half-relaxation time (Tr), and sustain time (Ts). When applied to lumbosacral musculature, interpretation may be influenced by changes in muscle stiffness that occur across the respiratory cycle. Understanding these fluctuations is essential for improving measurement consistency and data interpretation. Methods: Thirty healthy young adults (mean ± SD age = 21.07 ± 1.55 years) underwent TMG assessment of the erector spinae (ES) and latissimus dorsi (LD) at four distinct lung volumes: end-tidal inspiratory volume (ETIV), end-tidal expiratory volume (ETEV), total lung capacity (TLC), and residual volume (RV). Visual cues were used to guide participants’ respiratory phases. Paired-samples t-tests compared TMG parameters across respiratory conditions. Results: For the ES, significant differences were observed in Dm, Tr, and Ts between ETIV and ETEV (p ≤ 0.05), ETIV and TLC (p ≤ 0.05), and ETEV and RV (p ≤ 0.05). No statistically significant differences were identified for the LD (p ≥ 0.12). Conclusions: Some erector spinae contractile properties vary across the respiratory cycle, which may affect TMG outcomes. The findings of this research lend belief to the idea that a standardized respiratory phase during data collection may improve the reliability and comparability of TMG measurements involving trunk musculature. Future research could address the negative findings for latissimus dorsi and further determine which muscles require respiratory standardization. Full article

Although widely used, massage has not been reported to be effective in enhancing recovery from exercise-induced muscle damage in humans. Studies using massage-like interventions in animal models have, in contrast, consistently demonstrated a significant enhancement of muscle repair, reduction in muscle inflammation and enhanced return of muscle force following muscle damage. The physiology of muscle damage and repair and the putative physiological mechanisms of potential massage-induced muscle repair and post-damage recovery, including soreness sensation, edema, inflammation, protein synthesis and other related mechanisms, are reviewed in this context. Animal models have demonstrated that massage effectiveness in enhancing post-damage muscle repair is dictated by the timing, duration, force and technique of its application and may also be modified by age and sex effects. The potentially very narrow “window of effectiveness” of massage application for the enhancement of post-damage muscle repair in humans has yet to be defined. And the lack of demonstrated effectiveness for massage on post-damage muscle recovery may be due to the wide range and inconsistency of massage techniques, timing and methodologies applied in human studies. Until a specific massage application protocol is defined for massage efficacy in post-damage human muscle recovery, therapists will continue to work blind, using a variety of techniques which lack empirical validity and have an undemonstrated effectiveness for enhancing muscle repair. Full article

This study evaluated changes in upper trapezius muscle stiffness and choroidal blood flow velocity before and after ultrasonic therapy of the trapezius muscle. Participants included 27 healthy young adults in their 20 s (median age [Q1–Q3]: 21.0 [19.3–21.0]) without subjective shoulder pain. All participants received a single-session ultrasound intervention, and no control group was included. Intraocular pressure (IOP), systolic blood pressure (BP), diastolic BP, mean BP, heart rate (HR), ocular perfusion pressure (OPP), and salivary α-amylase (sAA) activity, a marker of autonomic nerve function, were assessed at baseline and after therapy. Stiffness of the upper trapezius muscle was evaluated using shear wave elastography, and choroidal hemodynamics were assessed by measuring the mean blur ratio (MBR), a relative index of macular blood flow velocity, using laser speckle flowgraphy. IOP, systolic BP, diastolic BP, mean BP, HR, OPP, sAA activity, and MBR reduced significantly after therapy. The shear elastic modulus of the trapezius muscle also decreased significantly. However, no significant correlations were observed among the parameters. Among healthy adults in their 20 s without shoulder pain, trapezius muscle ultrasound therapy may enhance parasympathetic activity, contributing to decreases in systemic and choroidal circulatory parameters. These findings indicate that ultrasound therapy for shoulder stiffness may influence local musculoskeletal characteristics, systemic and ocular circulation, and autonomic pathways. Full article

Myositis ossificans (MO) is a benign, self-limiting heterotopic ossification process that typically develops within soft tissues following trauma, although non-traumatic forms have also been described. Despite its benign nature, MO frequently represents a diagnostic challenge, particularly in its early stages when imaging findings may mimic aggressive soft-tissue tumors, leading to unnecessary biopsies or surgical interventions. This narrative review provides an updated overview of the classification, pathophysiology, and imaging features of myositis ossificans, with a specific focus on the time-dependent evolution of radiologic appearances across different imaging modalities. Radiologic findings are discussed according to disease stage, highlighting key diagnostic clues such as the zonal phenomenon and peripheral maturation pattern. In addition, the main entities included in the differential diagnosis are reviewed, with particular emphasis on imaging features that help distinguish myositis ossificans from soft-tissue sarcomas and other calcified or ossified lesions. Finally, current management strategies and the role of imaging in patient follow-up are summarized. A thorough understanding of the evolving imaging spectrum of myositis ossificans is essential for radiologists and clinicians to achieve an accurate diagnosis, guide appropriate management, and avoid overtreatment. Full article

Dynamic muscular endurance, the ability to lift a submaximal load until task failure, is a common measure in both cross-sectional and training studies. However, the repeatability of low-load muscular endurance in the knee extensors has not been well established. Establishing reliability metrics is essential to ensure that observed differences reflect true physiological changes rather than measurement error. The purpose of this study was to quantify the repeatability of low-load dynamic knee extensions performed to task failure. Forty healthy adults completed three visits, each consisting of one set of knee extensions at 20%, 30%, and 40% of one repetition maximum (1RM) to assess relative muscular endurance, and three sets at 20% 1RM on the contralateral leg to assess the impact of fatigue within a single session (fatigue curve). Intraclass correlation coefficients (ICCs), standard error of the measurement, and smallest detectable difference (SDD) were calculated. Repeatability ranged from moderate to excellent across conditions (ICC = 0.77–0.94). Lower loads and later sets demonstrated reduced repeatability compared with heavier loads and earlier sets. These results indicate that researchers and practitioners should consider load and fatigue curve effects in protocol design and SDDs when interpreting the meaningfulness of individual changes in knee extension muscular endurance. Full article

Physical exercise can influence cognitive performance and neurobiological processes, but evidence spans diverse modalities, intensities, and adult populations. Acute exercise represents a state of transient skeletal muscle activation that induces systemic signaling through metabolic, endocrine, and myokine-mediated pathways, which may contribute to neurocognitive modulation. To map the breadth of acute exercise–cognition research, characterize cognitive and biological outcomes, and identify consistent patterns and gaps. Studies of adults (≥18 years) involving a single exercise session or short microcycle (≤7 days) with pre–post assessment of cognition and/or neurobiological markers across any exercise modality (aerobic, resistance, high-intensity interval training/HIIT, combined, vibration, mind–body) were included. PubMed and CENTRAL were systematically searched, yielding 101 studies. Data were extracted using a structured framework capturing exercise modality, dose, cognitive domains, biomarkers, neuroimaging outcomes, population characteristics, and study design features. Most studies examined young adults (53%) or older adults (32%). Aerobic exercise predominated (62%), followed by resistance (18%) and combined modalities (12%). Moderate-to-vigorous aerobic exercise consistently improved executive function, processing speed, and working memory. Resistance exercise also enhanced executive function in several trials (31 studies). Neurobiological correlates included increases in Brain-Derived Neurotrophic Factor (BDNF), lactate, catecholamines, and prefrontal activation, though variability in sampling limited mechanistic conclusions. Acute exercise is consistently associated with improvements in executive function and processing speed across modalities. Standardized exercise protocols, biomarker timing, and cognitive assessments are needed to strengthen mechanistic synthesis. Full article

(1) Background: Handgrip strength (HGS) is a widely used indicator of neuromuscular function, with predictive values for health and performance outcomes. The aim of this study was to evaluate the intraday and interday reliability of maximal and explosive handgrip force–time metrics using the Kinvent K-Grip handheld dynamometer. (2) Methods: Thirty-four participants performed three maximal voluntary isometric contractions per hand across two testing days. Force–time data were analysed for peak force (PF), mean force (MF), peak rate of force development (RFD), time-specific RFD, impulse, and forces at fixed time points. Reliability was assessed using intraclass correlation coefficients (ICCs), standard error of measurement (SEM), minimal detectable change (MDC), and coefficient of variation (CV%). (3) Results: The device demonstrated excellent relative and absolute reliability for PF and MF across both days (ICC > 0.97; CV < 6%; MDC ≈ 5 kg). Later-phase explosive metrics (F250 and Imp200) showed good-to-excellent relative reliability (ICC = 0.88-0.99; CV = 4–14%), although with variable absolute reliability (MDC F250 ≈ 4–8 kg, MDC Imp200 ≈ 1 kg·s). For early-phase metrics, relative reliability was only moderate to good (ICC = 0.67–0.88) and characterised by a high degree of variability (CV = 15–22%). (4) Conclusions: The K-Grip handheld dynamometer is a reliable tool for cross-sectional assessments and for tracking larger maximal strength and later-phase force improvements at fixed time points. Early-phase explosive metrics are less suitable for monitoring intervention effects due to high measurement error and fatigue sensitivity. Full article

NASA intends to return humans to the Moon, where partial gravity will put them at risk of musculoskeletal deconditioning. Resveratrol (RSV) is a promising nutritional countermeasure that may protect muscle health during disuse; however, its efficacy and mechanism in simulated lunar gravity are unknown. Forty adult male Wistar rats underwent 14 days of normal loading or partial weight-bearing at 20% of normal loading (PWB20). Unloaded animals received daily RSV supplementation with or without an ERα antagonist to test whether ERα was required to mediate RSV benefits. Muscle function was longitudinally assessed, and a Western blot was used to quantify key signaling proteins in the soleus muscle. PWB20 led to a significant reduction in grip strength (−14.2%) associated with marked changes in electrophysiological muscle properties. RSV-supplemented animals performed better throughout the study, but not when Erα was inhibited. RSV supplementation resulted in a greater ERα phosphorylation ratio compared to PWB20 alone (3.5 vs. 1.91). These results suggest that RSV can mitigate muscle deconditioning in a lunar gravity analog and that ERα signaling is required. Full article

Research has yet to investigate the effects of unilateral Nordic hamstring training with a sloped platform (UNHT) on the fascicle length of the biceps femoris long head (BFlh FL) in previously injured legs. This study aimed to address this gap. A longitudinal pre–post design without a control group was used to examine the effects of 6 weeks of UNHT in eight young male athletes with a history of hamstring strain injury (HSI). Pre- and post-training measurements of middle and distal BFlh FL in the injured and uninjured legs were obtained using ultrasonography. At baseline, middle BFlh FL was significantly shorter in the injured leg than in the uninjured leg (86.0 ± 9.0 mm vs. 99.9 ± 7.6 mm, p < 0.001). Following UNHT, middle BFlh FL significantly increased in both the injured (105.8 ± 9.4 mm, p = 0.001) and uninjured legs (108.0 ± 10.3 mm, p = 0.596). Distal BFlh FL significantly increased in the injured leg (72.4 ± 7.1 mm to 85.7 ± 8.0 mm, p = 0.012), whereas the uninjured leg showed a smaller, non-significant change (72.8 ± 5.5 mm to 79.1 ± 7.5 mm, p = 0.069). These findings demonstrate that UNHT increased BFlh FL in previously injured legs. Because shorter BFlh FL and reduced eccentric strength are established risk factors for HSI, these adaptations may have implications for risk reduction; however, recurrence prevention was not assessed in this study. Full article

Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disorder caused by loss-of-function mutations in the dystrophin gene, leading to progressive muscle degeneration, motor decline, respiratory compromise, and cardiomyopathy. Diagnosis typically occurs in early childhood following recognition of motor delays, markedly elevated creatine kinase, and confirmatory genetic testing. Over the past decade, the therapeutic landscape for DMD has expanded substantially, evolving from exclusively supportive care to patient-centric multifaceted treatment paradigms, including corticosteroids, mutation-specific therapies, small molecule disease-modifying approaches, and gene replacement strategies. Despite these advances, no currently available therapy restores full-length dystrophin or completely halts disease progression. This review provides a clinically oriented comprehensive overview of currently Food and Drug Administration (FDA)-approved medications for DMD, with particular emphasis on corticosteroids, exon-skipping therapies, nonsense mutation readthrough agents, recently approved gene therapy, and select ongoing gene therapy trials. We summarize mechanisms of action, clinical efficacy, safety considerations, regulatory status, and highlight the challenges of integrating these therapies into longitudinal care. Through illustrative clinical vignettes, we highlight the real-world complexity of treatment selection, shared decision-making, and longitudinal care planning in contemporary DMD management. Full article

Major orthopedic limb surgery is often accompanied by external coaptation; the combined effect of these interventions can lead to muscle atrophy and functional impairment. Large animal models, including goats, are commonly used to study orthopedic interventions, yet longitudinal data on muscle changes after such interventions are limited. This study quantified gastrocnemius muscle adaptations in adult Boer-cross goats undergoing a clinically representative unilateral tibial segmental ostectomy and external coaptation protocol. Muscles on the operated side exhibited statistically significant decreases in mass, length, optimal fiber length, and CSA, and increases in nucleus density compared to muscles on the contralateral, non-operated side (p < 0.05). Although muscle properties showed partial recovery over time, mass and CSA remained 20–30% lower on the operated side than on the non-operated side at 12 months post-surgery despite cast removal at about 2 months post-surgery. Muscle CSA was positively correlated with bone mineral density and peak vertical ground reaction forces measured during the in vivo study. The extent of muscle recovery in the goat model was less than that observed for other mammalian models of hindlimb remobilization. More research is needed to understand the complex interaction between surgery, external coaptation, and muscle properties in the goat model. Full article

Peripheral arterial disease is a leading cause of amputation and/or death worldwide. Phosphodiesterase 4 (PDE 4) inhibitors demonstrated beneficial effects in ischemia–reperfusion (IR) settings, but whether PDE 4 inhibition protects skeletal muscle against IR deleterious effects is unknown. We therefore performed limb IR (two hours each) in twenty-one male Swiss mice (12–16-week-old) treated or not with Rolipram (1 mg/kg i.p. 30 min before ischemia and 5 min before reperfusion). The muscles were analyzed 4 h after the onset of ischemia. IR significantly increased leucocyte infiltration (93.13 ± 6.886 vs. 150.1 ± 18.38 cells/mg of muscle, p < 0.05) and apoptosis (Bax/Bcl2 ratio, +239%, p < 0.05), together with enhanced mitochondrial fission transcripts (+224% for Drp1, p < 0.01 and +368%, p < 0.0001 for Fis1), and decreased mitochondrial respiration and antioxidant defense. PDE 4 inhibition reduced leucocyte infiltration (150.1 ± 18.38 vs. 55.58 ± 13.83; p < 0.01) and apoptosis (+67%, NS) in association with reduced fission markers (+91% for Drp 1 and +111%, p < 0.05, for Fis 1). Muscle mitochondrial respiration did not improve. In conclusion, PDE 4 inhibition using Rolipram partly protected skeletal muscles against IR-induced deleterious effects. These data support further studies investigating the usefulness of leucocytes modulation in lower-limb IR and a potential beneficial effect of PDE 4 inhibition in peripheral arterial disease. Full article