Carpenter Nikolaus D, Wahl Aaron E, Butenas Alec L E, Toribio Sherwin, Caldwell Jacob T
Exercise and Sport Science Department, La Crosse, Wisconsin, USA.
Breathing Research and Therapeutics Center, Department of Physical Therapy, University of Florida, Gainesville, Florida, USA.
Physiol Rep. 2025 Aug;13(15):e70496. doi: 10.14814/phy2.70496.
Topical capsaicin reduces metaboreflex responses during post-exercise circulatory arrest (PECA) in males, but its effects in females and on microvascular responsiveness in either sex remain unclear. This study hypothesized that capsaicin would reduce blood pressure during PECA in males but not females, and enhance microvascular responsiveness in both sexes. Healthy males (n = 9) and females (n = 11) were randomly assigned to one of three conditions: capsaicin applied to the exercising arm, capsaicin applied to the non-exercising arm, or no capsaicin (control). Blood pressure was measured via the brachial artery during a handgrip exercise at 30% maximal voluntary contraction, followed by PECA using a rapid inflation cuff. Microvascular responsiveness was assessed with near-infrared spectroscopy (NIRS) during a post-occlusive reactive hyperemia test, conducted before and twice after capsaicin application. Capsaicin did not significantly alter blood pressure during PECA (p > 0.05), but a significant interaction was observed for microvascular responsiveness (p = 0.01). Although topical capsaicin did not attenuate metaboreflex-induced blood pressure changes, it enhanced microvascular responsiveness in the exercising arm compared to the systemic control. These findings suggest localized vascular benefits of capsaicin, but no clear impact on the metaboreflex. Further research is needed to clarify sex-specific responses to topical capsaicin.
局部使用辣椒素可降低男性运动后循环骤停（PECA）期间的代谢反射反应，但其对女性的影响以及对两性微血管反应性的影响尚不清楚。本研究假设辣椒素会降低男性而非女性在PECA期间的血压，并增强两性的微血管反应性。健康男性（n = 9）和女性（n = 11）被随机分配到三种情况之一：将辣椒素应用于运动手臂、将辣椒素应用于非运动手臂或不使用辣椒素（对照）。在30%最大自主收缩的握力运动期间通过肱动脉测量血压，随后使用快速充气袖带进行PECA。在辣椒素应用前和应用后两次进行的闭塞后反应性充血试验期间，用近红外光谱（NIRS）评估微血管反应性。辣椒素在PECA期间未显著改变血压（p > 0.05），但在微血管反应性方面观察到显著的交互作用（p = 0.01）。虽然局部使用辣椒素并未减弱代谢反射引起的血压变化，但与全身对照相比，它增强了运动手臂的微血管反应性。这些发现表明辣椒素具有局部血管益处，但对代谢反射没有明显影响。需要进一步研究以阐明对局部使用辣椒素的性别特异性反应。
