Sex differences in the vascular response to sympathetic activation during acute hypoxaemia.
Sex differences in the vascular response to sympathetic activation during acute hypoxaemia.
复制标题
DOI：
10.1113/ep089461
复制
发表时间：
2021-08
影响因子：
2.7
通讯作者：
Limberg JK
中科院分区：
文献类型：
--
作者：
Jacob DW;Harper JL;Ivie CL;Ott EP;Limberg JK
交感神经系统的激活引起血管收缩和外周血流量的减少。交感神经介导的血管收缩可能在全身缺氧期间减弱以维持氧气输送;然而，在主要为男性的参与者中，交感神经介导的血管收缩在低氧血症期间得以保留甚至增强。鉴于低氧血管控制的性别特异性差异的潜力，以前的结果是有限的应用。我们检验了年轻女性在稳态低氧血症时减弱交感神经介导的血管收缩的假设，而男性则不然。健康的年轻男性（n=13，25±4岁）和女性（n=11，24±4岁）完成了两项试验，包括在基线常氧和稳态低氧血症期间进行2分钟冷加压试验（CPT，一种公认的交感兴奋性刺激）。连续测量每搏血压（BP，手指光电体积描记法）和前臂血流量（FBF，静脉闭塞体积描记法）。计算总血管传导率和前臂血管传导率（分别为TVC和FVC）。计算CPT最后1分钟内TVC和FVC相对于稳态的变化（Δ），并评估常氧和全身缺氧之间的差异。在男性中，缺氧时CPT期间TVC的降低幅度大于常氧时（ΔTVC，p=0.02），而在女性中，不同条件下的ΔTVC无差异（p=0.49）。在男性中，常氧和缺氧之间的ΔFVC无差异（p=0.92）。在女性中，CPT期间FVC的降低在缺氧期间减弱（ΔFVC，p<0.01）。我们证实，年轻男性在低氧血症期间交感神经介导的血管收缩是保留或增强的，而年轻女性在低氧血症期间交感神经激活的外周血管反应性减弱。结果推进了我们对缺氧血管控制中性别相关差异的理解。
Activation of the sympathetic nervous system causes vasoconstriction and a reduction in peripheral blood flow. Sympathetically-mediated vasoconstriction may be attenuated during systemic hypoxia to maintain oxygen delivery; however, in predominantly male participants sympathetically-mediated vasoconstriction is preserved or even enhanced during hypoxemia. Given the potential for sex-specific differences in hypoxic vascular control, prior results are limited in application. We tested the hypothesis that young women attenuate sympathetically-mediated vasoconstriction during steady-state hypoxemia, whereas men do not. Healthy young men (n=13, 25±4 yrs) and women (n=11, 24±4 yrs) completed two trials consisting of a 2-min cold pressor test (CPT, a well-established sympathoexcitatory stimulus) during baseline normoxia and steady-state hypoxemia. Beat-to-beat blood pressure (BP, finger photoplethysmography) and forearm blood flow (FBF, venous occlusion plethysmography) were measured continuously. Total and forearm vascular conductance (TVC and FVC, respectfully) were calculated. A change (Δ) in TVC and FVC from steady-state during the last 1-min of CPT was calculated and differences between normoxia and systemic hypoxia were assessed. In men, the reduction in TVC during CPT was greater during hypoxia compared to normoxia (ΔTVC, p=0.02), whereas ΔTVC did not differ between conditions in women (p=0.49). In men, ΔFVC did not differ between normoxia and hypoxia (p=0.92). In women, the reduction in FVC during CPT was attenuated during hypoxia (ΔFVC, p<0.01). We confirm sympathetically-mediated vasoconstriction is preserved or enhanced during hypoxemia in young men, whereas peripheral vascular responsiveness to sympathetic activation during hypoxemia is attenuated in young women. Results advance our understanding of sex-related differences in hypoxic vascular control.