Search Results (1,040)

Objective: To determine whether contrast therapy improves recovery after climbing-specific forearm fatigue in amateur climbers. Methods: In a randomized repeated-measures trial, 40 climbers were allocated to passive recovery (n = 20) or Game Ready contrast therapy (n = 20). Both groups completed a fixed-task intermittent fingerboard protocol on a 20 mm edge using a half-crimp grip, with 7 s of work and 3 s of rest for five sets; the load was not individualized to climbing-specific maximal finger-flexor force. The intervention group received bilateral forearm treatment consisting of alternating 1 min cold (3 °C) and heat (45 °C) phases combined with pneumatic compression ranging from 15 to 75 mmHg. Sessions lasted 20 min and were administered immediately after post-fatigue testing, at 24 h and 48 h, and then three times weekly on alternate days for 8 weeks, for a total of 27 sessions. Outcomes were assessed at baseline, immediately after fatigue, at 24 h and 48 h, and after 8 weeks. Outcomes included perfusion, reactive hyperemia, stiffness, pressure pain threshold, grip strength, perceived recovery, creatine kinase, and interleukin-6. Results: Immediate post-fatigue responses were comparable. Contrast therapy produced greater 24 h and 48 h resting perfusion responses (+7.28 percentage points, 95% CI 6.58 to 7.98; +7.62, 95% CI 6.94 to 8.31; both adjusted p < 0.001). At week 8, peak hyperemic perfusion improved more with contrast therapy (+6.21 PU, 95% CI 5.62 to 6.79; p < 0.001). Recovery favored contrast therapy for stiffness at 48 h (−71.7 N/m, 95% CI −75.6 to −67.8), pressure pain threshold at week 8 (+8.1 N/cm², 95% CI 7.3 to 8.8), and grip strength at 48 h (+7.8 kgf, 95% CI 7.3 to 8.3; all p < 0.001). CK and IL-6 differences were transient, and no serious adverse events or intervention-related discontinuations were recorded. Conclusions: Contrast therapy was associated with more favorable cutaneous perfusion, post-occlusive reactive hyperemia-derived, and neuromechanical recovery outcomes, whereas biochemical differences were limited and time-dependent. The vascular findings do not establish improved endothelial function or nitric-oxide-mediated vasodilation because these mechanisms were not directly assessed. Trial registration: ISRCTN49499065 on 23 June 2025. Full article

Coronary artery vasospasm (CAV) is a transient, reversible constriction of the epicardial coronary arteries that reduces coronary blood flow and may cause myocardial ischemia. Despite its clinical significance, CAV remains underdiagnosed and can present as chest pain, acute coronary syndrome, malignant arrhythmias or sudden cardiac death. Vasospasm may occur in both angiographically normal coronary arteries and at sites of pre-existing atherosclerotic stenosis. The pathophysiology of CAV is multifactorial and involves vascular smooth muscle cells (VSMCs) hyperreactivity, endothelial dysfunction, chronic inflammation and autonomic dysregulation. VSMCs contraction is mediated by phosphorylation of the myosin light chain (MLC) through calcium (Ca²⁺)/calmodulin-dependent myosin light chain kinase (MLCK), while relaxation is regulated by myosin light chain phosphatase (MLCP). Increased intracellular Ca²⁺ levels and enhanced Ca²⁺ sensitivity contribute to excessive vasoconstriction. Rho-kinase (ROCK) plays a pivotal role in sustained vasospasm by inhibiting MLCP, thereby promoting prolonged smooth muscle contraction. Endothelial dysfunction contributes to CAV by disrupting normal vascular tone regulation, largely as a result of decreased nitric oxide (NO) mediated vasodilation. Chronic low-grade inflammation and oxidative stress exacerbate both endothelial dysfunction and VSMCs contraction. Understanding these molecular mechanisms is essential for identifying novel therapeutic targets. Emerging treatment strategies, including ROCK inhibitors, endothelin receptor antagonists and anti-inflammatory agents, may improve outcomes in patients with refractory CAV. Full article

Background/Objectives: Hemodynamic disturbances in sepsis and septic shock arise from the vasoactive effects of inflammatory mediators involved in the immune response. Relaxin-1 is a pleiotropic hormone associated with inflammation, angiogenesis, tissue repair, and vasodilation. This study aimed to investigate the changes in relaxin-1 levels in septic shock and to evaluate their association with mortality. Methods: This prospective observational study was conducted in a Level II intensive care unit. Demographic characteristics, vital signs, APACHE II and SOFA scores, comorbidities, and routine laboratory parameters were recorded at admission and at 48 h. Serum relaxin-1 levels were measured at both time points and analyzed in relation to survival status. Binary logistic regression was additionally performed to evaluate variables associated with mortality in a multivariable framework. Results: A total of 48 patients with sepsis and septic shock were included (54.2% female; mean age 73.4 ± 14.7 years). Overall mortality was 33.3%. Relaxin-1 levels significantly increased from baseline (11.25 ± 4.85 pg/mL) to 48 h (12.64 ± 4.81 pg/mL) (p = 0.047). Baseline relaxin-1 levels were significantly higher in non-survivors compared to survivors (14.62 ± 4.47 pg/mL vs. 11.65 ± 4.73 pg/mL, p = 0.043). Conclusions: Elevated Relaxin-1 levels were associated with mortality in patients with sepsis and septic shock. The observed increase in Relaxin-1 during early follow-up suggests a potential link with the underlying pathophysiological processes. Although Relaxin-1 was associated with mortality, its independent prognostic value could not be established in multivariable analysis due to the limited sample size. Larger, adequately powered multicenter studies are required to confirm these findings. Full article

Background/Objectives. Pulmonary arterial hypertension (PAH) is a rare but severe disease which leads to right ventricular (RV) maladaptation, failure and death. Currently approved drugs have limited impact on disease progression. A multitarget strategy consisting of adenosine A₂B receptor activation and phosphodiesterase-4 (PDE4) inhibition, combined with human mesenchymal stromal cells (hMSCs) therapy, was tested in experimental PAH. The main objective was to determine whether the combination improved pulmonary hemodynamics, vascular remodeling, and RV function, given the limited disease-modifying effects of currently approved vasodilators. Methods. Vascular reactivity was assessed in isolated rat pulmonary artery rings exposed to the dual-target compound (LASSBio-1860) alone or in the presence of either ZM-241385 or MRS-1706. PAH was induced in male Wistar rats with monocrotaline (MCT, 60 mg·kg⁻¹) and confirmed by a decrease in pulmonary artery acceleration time to ejection time ratio (PAAT/TET). Animals were randomized to receive vehicle, hMSC (single i.v. dose, 1 × 10⁵ cells), LASSBio-1860 (62 mg·kg⁻¹·day⁻¹, p.o., 14 days), or their combination. Outcomes included PAAT/TET and RV cardiac output (RV-CO) by echocardiography, RV systolic pressure (RVSP) by direct puncture, Fulton index and RV wall thickness, lung histology (perivascular cell counts and wall thickness), and RV protein expression (TGF-β, CaMKII) by Western blot. Results. LASSBio-1860 produced endothelium-independent vasorelaxation of rat pulmonary arteries, consistent with A₂B agonism and PDE4 inhibition. In MCT-induced PAH, combination of LASSBio-1860 and hMSCs resulted in recovery of PAAT/TET and RV-CO, decrease in RVSP, RV hypertrophy, vascular inflammation and remodeling by downregulation of ventricular TGF-β and CaMKII. Conclusions. Combination of LASSBio-1860 with hMSC improved RV function, attenuated pulmonary hypertension, RV and vascular remodeling, and reduced inflammatory/proliferative signaling in MCT induced-PAH, supporting a promising multitarget therapeutic strategy for PAH. Full article

The right ventricle (RV) is a primary determinant of outcomes in cardiac critical care. RV dysfunction independently predicts morbidity and mortality in conditions such as acute coronary syndromes, pulmonary embolism, and cardiogenic shock. This review synthesizes RV evaluation and management by integrating physiologic principles with bedside diagnostic and therapeutic strategies. The RV is exceptionally sensitive to acute afterload increases due to its adaptation to low-pressure pulmonary circulation. Evaluation utilizes a multimodal approach combining echocardiography, invasive hemodynamics, and specifically the pulmonary artery pulsatility index and central venous pressure/pulmonary capillary wedge pressure (CVP/PCWP) ratio and biomarkers. Management focuses on three pillars: individualized preload optimization, afterload reduction via selective pulmonary vasodilators, and contractility augmentation with inotropes. For refractory cases, mechanical circulatory support options like Impella RP, ProtekDuo, and VA-ECMO provide critical bridges to recovery or transplantation. Full article

The calcitonin gene-related peptide (CGRP) is a 37-amino acid neuropeptide belonging to the calcitonin family, discovered as a product of alternative splicing of the calcitonin gene. CGRP has emerged as a pleiotropic signaling molecule with widespread distribution in the central and peripheral nervous systems, particularly within primary sensory neurons. This narrative review synthesizes current knowledge on the CGRP system, integrating recent advances in its molecular structure, gene organization, and post-translational processing with high-resolution structural insights into its heterodimeric receptor complex (CLR-RAMP1) obtained through cryo-electron microscopy. We also include long-term safety data on anti-CGRP monoclonal antibodies, emerging cardiovascular risk signals, and novel therapeutic applications in vestibular migraine and pediatric populations. The intracellular signaling cascades activated by CGRP, including the canonical cAMP-PKA pathway, MAP kinase activation, and context-dependent calcium signaling, are discussed in relation to its diverse physiological functions. These encompass vasodilation, nociception modulation, neurogenic inflammation, gastrointestinal motility, bone metabolism, tissue regeneration, and energy homeostasis. The central role of CGRP in migraine pathophysiology is examined to understand the development of targeted therapies. The current pharmacological landscape is reviewed, including the evolution of small-molecule CGRP receptor antagonists (gepants) through three generations and the four approved monoclonal antibodies targeting CGRP or its receptor, with comparative analysis of their efficacy, safety profiles, and clinical positioning. Beyond migraine, emerging and predominantly preclinical roles of the CGRP system are discussed in chronic pain, osteoarthritis, cardiovascular diseases, sepsis, cancer (particularly bone metastases and tumor microenvironment immunomodulation), and neurodegenerative disorders such as Alzheimer’s disease. In these areas, the available evidence remains heterogeneous and, in most cases, is not yet sufficient to support clinical translation. Finally, future directions are discussed, including the development of stable CGRP analogs, allosteric modulators, and the potential expansion of therapeutic applications into oncology, intensive care medicine, and neuroprotection. Full article

Background/Objectives: Type 2 Diabetes Mellitus (T2DM) is characterized by insulin resistance and chronic hyperglycemia, which significantly impair vascular function. In experimental T2DM models, the vascular endothelium is compromised, showing decreased vasodilator responses. Vitamin D3 has emerged as a promising intervention for improving glycemic parameters and restoring endothelial function. This study evaluated the effects of vitamin D3 (0.25 and 0.50 µg/kg/day) administered for 4 and 8 weeks on the ex vivo aortic vascular reactivity of T2DM rats. Methods: T2DM was induced in male Wistar rats via a high-fat, normoprotein diet and streptozotocin (30 mg/kg, i.p.). Groups included normal control, diabetic control, metformin, and vitamin D3 (0.25 or 0.50 µg/kg/day). Following 4 or 8 weeks of treatment, thoracic aortic segments were isolated for ex vivo vascular reactivity studies to assess responses to vasoconstrictor and vasorelaxant agents. Results: Vitamin D3 treatment improved glycemic profiles; the 0.25 µg/kg dose reduced fasting glucose, while the 0.50 µg/kg dose lowered glycated hemoglobin at 8 weeks. Endothelium-dependent relaxation induced by acetylcholine was significantly increased in diabetic rats treated with vitamin D3 at both doses over 4 weeks compared to diabetic controls. Moreover, vitamin D3 prevented the attenuation of maximal contractile responses to phenylephrine observed in untreated diabetic rats at 8 weeks. Conclusions: Vitamin D3 supplementation restores endothelial function and improves vascular reactivity in an experimental T2DM model. These findings suggest that vitamin D3 may mitigate vascular complications by enhancing vasorelaxation and maintaining contractile integrity. Full article

Background/Objectives: Transradial access (TRA) is the preferred route for coronary catheterization, yet its consequences for radial artery vasoreactivity and hemodynamic parameters remain incompletely characterized. We prospectively quantified TRA-induced functional impairment, its clinical determinants, and the association of baseline parameters with post-procedural outcomes. Methods: Ninety-four consecutive patients undergoing elective TRA were assessed at baseline, 24 h, and one month using high-resolution Doppler ultrasound. Nine vascular parameters were measured: flow-mediated dilation (FMD), nitroglycerin-mediated dilation (NMD), peak systolic velocity (PSV), resistive index (RI), pulsatility index (PI), resting and hyperemic velocity-time integral, hyperemic blood flow volume, and lumen diameter. Non-parametric methods were applied throughout. Results: FMD declined at 24 h (−31.2%; p < 0.001) and showed no significant recovery at one month (p = 0.08 vs. 24 h). NMD showed a greater acute decline (−36.6%; p < 0.001) with partial but statistically significant recovery at one month (p < 0.001). PSV recovered fully by one month; RI fell below baseline, consistent with compensatory microvascular vasodilation. Radial artery lumen diameter remained significantly below baseline at one month. Radial artery occlusion occurred in 4 patients (4.3%), all with spontaneous recanalization. Female sex was selectively associated with greater NMD reduction (ΔNMD −8.3% vs. −5.8%; p = 0.005) without a statistically significant FMD difference (p = 0.40). Older age correlated with impaired FMD recovery at one month (ρ = −0.62; p < 0.001) but not with NMD outcomes. Baseline PSV demonstrated the highest discriminatory performance for significant FMD decline (AUC = 0.73). Conclusions: TRA causes multidomain, persistent radial artery functional impairment at one month, with distinct recovery trajectories for endothelial and smooth muscle function. Female sex and advanced age are selective determinants of injury and recovery, respectively. A pre-procedural phenotype comprising baseline diameter, PSV, RI, and age is associated with post-procedural outcomes and supports further investigation of pre-procedural phenotyping as a candidate framework for risk stratification. Full article

Background: Focal entrapment of the Common Peroneal (Fibular) nerve (CPN) is the most frequent lower-extremity nerve entrapment yet it can be difficult to diagnose clinically. The Phoenix Sign—an increase in extensor hallucis longus (EHL) motor strength following lidocaine injection—may assist diagnosis. Additional observed effects include improved arterial perfusion and Doppler waveforms. Methods: In this double-blinded, randomized small pilot study, only four patients (N = 4) with diabetic peripheral neuropathy underwent bilateral peripheral nerve blocks with lidocaine or papaverine. The first leg to be tested was randomized; the contralateral leg received a different agent that was randomized initially. Pre- and post-block assessments included motor strength, Doppler velocity of dorsalis pedis and posterior tibial arteries, and near-infrared spectroscopy for microvascular perfusion. Results: All patients demonstrated increased EHL motor strength after injection with either agent. Doppler waveforms of the dorsalis pedis artery improved: lidocaine produced a 151.7% increase in blood flow velocity (p = 0.03), whereas papaverine produced a 16.8% increase (p = 0.19). Posterior tibial artery flow increased by 37.4% with lidocaine (p = 0.06) and 13.9% with papaverine (p = 0.33), but neither was statistically significant. No changes in oxygen saturation, oxyhemoglobin, deoxyhemoglobin, or total hemoglobin were observed using near-infrared spectroscopy. The consistency of motor responses across subjects supports the validity of the Phoenix Sign as a diagnostic tool. Conclusions: Peripheral nerve blocks with lidocaine or papaverine improved motor strength and macrovascular function in patients with diabetic peripheral neuropathy, though microvascular changes were not detected. These preliminary findings are consistent with the Phoenix Sign phenomenon and support further study as a potential clinical indicator. While these preliminary findings indicate support as a diagnostic tool, they are preliminary and hypothesis-generating for evaluating the Phoenix Sign as a potential clinical indicator of CPN entrapment and highlight the need for larger studies to evaluate vascular responses. Trial Registration: NCT06919289 (retrospectively registered 8 April 2025). Full article

Adenosine has emerged as a central metabolic signal linking cellular stress to systemic physiological adaptation. Under conditions such as hypoxia, ischemia, inflammation, and tissue injury, extracellular adenosine triphosphate (eATP) released from stressed cells is sequentially metabolized by the ectonucleotidases CD39 and CD73, generating adenosine that accumulates in the extracellular microenvironment. This stress-responsive nucleoside activates four G-protein-coupled receptors (A1, A2A, A2B, and A3), triggering intracellular signaling networks including the cyclic adenosine monophosphate–protein kinase A (cAMP–PKA), mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase–protein kinase B (PI3K–Akt), and hypoxia-inducible factor-1 alpha (HIF-1α) pathways. Through these integrated mechanisms, adenosine orchestrates diverse physiological processes such as vascular regulation, metabolic adaptation, immune modulation, and cellular survival. In the cardiovascular system, adenosine promotes coronary vasodilation and ischemic preconditioning, limiting reperfusion injury. In pulmonary tissues, it mediates acute anti-inflammatory responses but may also drive chronic fibrotic remodeling. Within the central nervous system, adenosine functions as a neuromodulator regulating neuronal excitability, sleep–wake homeostasis, and neuroprotection. In the tumor microenvironment, hypoxia-driven adenosine accumulation suppresses cytotoxic T cell and natural killer activity, facilitating immune evasion and tumor progression. Collectively, adenosine signaling represents a central integrative network that links metabolic stress sensing to coordinated cellular adaptation while simultaneously emerging as a clinically actionable therapeutic target across cardiovascular, inflammatory, neurological, and oncological diseases. Full article

Background/Objectives: Nobiletin, one of the main components of citrus peel, exhibits potent antioxidant, anti-inflammatory, and metabolic regulatory properties. However, its effect on obesity-associated vasculopathay remains unknown. We aim to investigate the effect of nobiletin in ameliorating oxidative stress and endothelial dysfunction induced by a high-fat diet (HFD). Methods: Male C57BL/6J mice were fed a HFD (60 kcal% fat) or normal chow for four months and orally administered with vehicle or nobiletin (50 mg/kg/day) for 8 weeks. Vasoreactivity in aortas was measured on a wire myograph. Primary rat aortic endothelial cells (RAECs) were isolated from Sprague-Dawley rats for in vitro study. Protein expressions were detected by Western blot. Superoxide production was determined by fluorescence imaging. Results: Exposure to high glucose increased the phosphorylation of JNK (Tyr185) and decreased the protein expressions of Nrf2 and HO-1, as well as downregulated the phosphorylation of AMPK and eNOS (Ser1177) in RAECs. This led to reduced nitric oxide (NO) generation and elevation of oxidative stress. High glucose induction also impaired the endothelium-dependent relaxations (EDRs) in murine aortas. These high glucose-induced impairments were restored by co-treatment of nobiletin (1 μM or 10 μM) whereas effects of nobiletin were abolished by AMPK inhibitor Compound C. The DIO-induced diabetic animal model showed increased body weight and blood pressure, imbalance of glucolipid metabolism, impaired EDRs, and elevated oxidative stress in aortas. AMPK/eNOS and Nrf2/HO-1 pathways were downregulated in aortas from DIO mice. Oral administration of nobiletin could at least partially reverse the above damage. Conclusions: Nobiletin ameliorates endothelial dysfunction by reducing oxidative stress and enhancing NO bioavailability upon activation of AMPK/eNOS and Nrf2/HO-1 pathways in obese diabetic mice. Full article

Myocardial bridging (MB) is a congenital coronary anomaly characterized by systolic compression of the intramyocardial arterial segment and delayed early diastolic artery relaxation, resulting in reduced vessel luminal diameter in diastole. Current evidence suggests that MB, particularly in the left anterior descending artery, may cause anginal symptoms and/or myocardial ischemia through several different pathophysiological and cellular mechanisms acting independently or synergistically: (1) delayed early diastolic relaxation of intramyocardial arterial segment; (2) impaired endothelial-dependent vasodilation with vessel smooth muscle cell hyperactivity in the coronary artery with MB, especially within the bridged segment; (3) focal (septal) ischemia due to “septal steal” phenomenon; and (4) development and progression of an atherosclerotic lesion in the coronary artery segment proximal to MB. Patients with isolated-MB may also experience anginal pain and/or myocardial ischemia due to concomitant structural and/or functional abnormalities of the coronary microcirculation. Both MB and coronary microvascular dysfunction refer to a subgroup of patients with angina and/or ischemia with non-obstructive coronary arteries (ANOCA/INOCA). Therefore, it may be challenging to determine whether MB is causing anginal pain and/or ischemia, particularly since both phenomena have also been reported without MB’s existence. Therefore, comprehensive coronary physiology testing should be encouraged in patients with this coronary anomaly to identify the underlying cause of anginal pain and/or myocardial ischemia, enabling optimal therapeutic strategies in these patients. This review is focused on different pathophysiological and cellular mechanisms of MB-related angina and/or ischemia and future perspectives in the functional assessment of MB severity, bearing in mind the complexity of coronary physiology in the presence of this anomaly. Full article

Background/Objectives: The ACE2/Ang-(1–7)/Mas receptor axis is a protective, counter-regulatory component of the RAAS that opposes Ang II/AT₁R-mediated vasoconstriction. The present study evaluated the pharmacological effects of Ang-(1–7) in the rat inferior vena cava (IVC), a venous capacitance vessel involved in the regulation of venous return and cardiac preload. We hypothesized that Ang-(1–7) exerts anti-contractile effects in the rat inferior vena cava through activation of potassium channel-dependent mechanisms in venous smooth muscle. Methods: Isolated IVC rings from Wistar rats were studied using organ bath assays. Ang-(1–7) effects were assessed on pre-constriction induced by angiotensin II (Ang II), phenylephrine (PE), endothelin-1 (ET-1), and thromboxane A₂ analog (U46619). Responses were recorded and quantified. Mechanistic involvement of nitric oxide (NO), prostaglandins, soluble guanylate cyclase (sGC), and K⁺ channels was evaluated using specific pharmacological inhibitors. Results: Ang-(1–7) attenuated Ang II-induced contraction. The effect was markedly reduced by tetraethylammonium (TEA), indicating a predominant role of potassium channel-dependent mechanisms in venous smooth muscle. In contrast, inhibition of nitric oxide synthase, soluble guanylate cyclase, or cyclooxygenase had minimal influence. Ang-(1–7) also produced concentration-dependent relaxation in PE-, ET-1-, and U46619-precontracted vessels, demonstrating agonist-dependent anti-contractile activity. Conclusions: Ang-(1–7) exerts significant anti-contractile effects in the rat inferior vena cava primarily through activation of TEA-sensitive K⁺ channels in venous smooth muscle. These findings demonstrate functional activity of the ACE2/Ang-(1–7)/Mas axis in a major venous capacitance vessel and provide mechanistic insight into Ang-(1–7)-mediated modulation of venous tone, supporting further investigation in in vivo models. Full article

Background/Objectives: Body Protection Compound-157 (BPC 157) is a stable gastric pentadecapeptide with cytoprotective, pro-angiogenic, and nitric oxide (NO)-modulating properties that has gained increasing attention for its therapeutic potential. Although vasodilatory effects have been demonstrated in animal models, functional evidence in human arterial tissue remains limited. This study investigated the effects of BPC 157 on vascular tone in human internal mammary artery (IMA) rings and evaluated the contribution of endothelial NO signaling. Methods: Residual IMA segments obtained from elective coronary artery bypass graft surgeries (n = 12) were dissected into endothelium-intact and endothelium-denuded rings. Following equilibration, the rings were challenged by phenylephrine (PheE; 3 × 10⁻⁶ M) to induce contraction. Cumulative concentration–response curves of BPC 157 (0.01–1 mg/mL) for five consecutive doses were constructed. The involvement of NO was assessed by BPC 157 dose–response curves in the nitric oxide synthase (NOS) inhibitor Nω-nitro-L-arginine methyl ester (L-NAME; 10⁻⁶ M) pre-incubated rings. Maximum force of contraction, area under the curve, maximum response (Emax), and negative logarithm of the half-maximal effective concentration (pEC50) values were analyzed. Results: BPC 157 produced a concentration-dependent reduction in PheE-induced contraction in both groups, with significantly greater relaxation in endothelium-intact rings (p < 0.05). L-NAME increased contractile responsiveness in intact rings and attenuated BPC 157-induced relaxation. Under NOS inhibition, differences between groups progressively diminished and concentration–response curves converged at higher concentrations. Emax analysis demonstrated that endothelial integrity markedly enhanced maximal vasorelaxation, whereas this advantage was largely abolished after NOS inhibition. Conclusions: BPC 157 induces concentration-dependent vasorelaxation in human arterial tissue, predominantly mediated via an endothelium-dependent NO pathway. Endothelial integrity primarily enhances maximal efficacy, while residual effects indicate additional mechanisms. These findings provide early mechanistic evidence for the vascular activity of BPC 157, although further molecular and in vivo studies are required to clarify its clinical relevance. Full article

A male castrated Shih Tzu was evaluated for recurrent nocturnal episodes of acute respiratory distress accompanied by hemoptysis and transient erythrocytosis. The dog was clinically normal between episodes, but each nighttime event was severe and prompted repeated emergency visits. During each emergency presentation, thoracic radiographs revealed severe diffuse interstitial-to-alveolar pulmonary infiltrates, and packed cell volume showed marked but reversible increases. A stepwise diagnostic evaluation, including serial indirect blood pressure measurement, coagulation assessment, echocardiography, and bronchoscopy with bronchoalveolar lavage, progressively excluded typical infectious, cardiac, structural, and coagulopathic causes of hemoptysis and acute respiratory distress. Given the stereotyped pattern of near-acute crises with diffuse pulmonary infiltrates and hemoptysis, mechanisms analogous to noncardiogenic pulmonary edema or exercise-induced pulmonary hemorrhage were considered. Therapeutic trials with sildenafil and furosemide failed to prevent further nocturnal recurrences. Considering concurrent transient PCV surges and the proposed role of catecholamine-driven splenic contraction as a rapidly mobilizable erythrocyte reservoir, a sympathetically mediated process was suspected, and α₁-adrenergic blockade with prazosin was initiated. Following prazosin therapy, sustained clinical remission was achieved, with no further emergency episodes over a 17.5-month follow-up period. The response may have reflected multiple pharmacological effects of prazosin, including attenuation of sympathetically mediated splenic α₁-adrenergic activity, systemic vasodilation, and reduction in venous return. This unique case suggests that dysregulation of the sympathetic nervous system may have contributed to the recurrent hemoptysis and acute respiratory distress and highlights adrenergic modulation as a potential therapeutic consideration in similar cases. Full article