Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri.
Am J Physiol Heart Circ Physiol. 2022 Jun 1;322(6):H1072-H1079. doi: 10.1152/ajpheart.00140.2022. Epub 2022 Apr 29.
Acute increases in sympathetic nervous system activity (SNA) often elicit peripheral vasoconstriction and increases in blood pressure (BP). Given sympathetic support of BP is modulated by ovarian sex hormones (e.g., estradiol), we sought to examine the effect of menstrual cycle and oral hormonal contraceptive pill (OC) phase on the hemodynamic response to acute increases in SNA. We hypothesized sympathoexcitation via cold pressor test (CPT) would elicit greater peripheral vasoconstriction and increases BP in females with natural menstrual cycles (NC) compared with females taking OC. We further hypothesized that SNA-mediated vasoconstriction would be attenuated during the high estradiol (HE) phase versus the low estradiol (LE) phase of the menstrual/pill cycle. Female NC ( = 11, 25 ± 1 yr) and OC ( = 10, 24 ± 1 yr) participants were studied during the LE (early follicular, placebo pill) and HE (late follicular, active pill) phase of the menstrual/pill cycle. BP (finger photoplethysmography), heart rate (HR, ECG), and forearm blood flow (FBF, venous occlusion plethysmography) were measured during a 5-min baseline and a 2-min CPT. CPT elicited an increase in BP in both groups (time, < 0.01). During CPT, OC participants exhibited greater and sustained increases in HR compared with NC participants (group × time, < 0.01). Higher HRs were met with increases in FBF in OC participants during the CPT, which was not observed in NC participants (group × time, < 0.01). OC participants exhibit greater increases in HR, and paradoxical vasodilation during acute sympathetic activation compared with NC participants. Group differences are unaffected by menstrual/pill phase. Acute increases in sympathetic nervous system activity often elicit peripheral vasoconstriction and increases in blood pressure (BP). Given sympathetic support of BP is modulated by ovarian sex hormones (e.g., estradiol), we sought to examine the effect of menstrual cycle and oral hormonal contraceptive pill (OC) phase on the hemodynamic response to acute increases in sympathetic nervous system activity via the cold pressor test. We show OC participants exhibit paradoxical vasodilation during acute sympathetic activation compared with participants with natural menstrual cycles; notably, group differences were unaffected by menstrual/pill phase.
急性增加交感神经系统活动（SNA）通常会引起外周血管收缩和血压升高（BP）。鉴于卵巢性激素（例如雌二醇）调节 BP 的交感神经支持，我们试图研究月经周期和口服避孕药（OC）阶段对冷加压试验（CPT）中 SNA 急性增加的血液动力学反应的影响。我们假设通过冷加压试验（CPT）引发的交感兴奋会引起服用 OC 的女性比自然月经周期（NC）的女性产生更大的外周血管收缩和血压升高。我们进一步假设，在月经/药丸周期的高雌二醇（HE）阶段与低雌二醇（LE）阶段，SNA 介导的血管收缩会减弱。在月经/药丸周期的 LE（早期卵泡期，安慰剂药丸）和 HE（晚期卵泡期，活性药丸）阶段，研究了 11 名 NC 女性（25 ± 1 岁）和 10 名 OC 女性（24 ± 1 岁）参与者。在 5 分钟的基线和 2 分钟的 CPT 期间测量血压（手指光电容积描记法）、心率（HR，心电图）和前臂血流（FBF，静脉闭塞体积描记法）。CPT 引起两组血压升高（时间，<0.01）。在 CPT 期间，OC 参与者的 HR 升高且持续高于 NC 参与者（组×时间，<0.01）。在 CPT 期间，OC 参与者的 HR 升高伴随着 FBF 的增加，但在 NC 参与者中没有观察到（组×时间，<0.01）。与 NC 参与者相比，OC 参与者在急性交感神经激活期间表现出更大的 HR 增加和矛盾性血管舒张。组间差异不受月经/药丸阶段的影响。急性增加交感神经系统活动通常会引起外周血管收缩和血压升高（BP）。鉴于卵巢性激素（例如雌二醇）调节 BP 的交感神经支持，我们试图研究月经周期和口服避孕药（OC）阶段对急性增加交感神经系统活动通过冷加压试验对血液动力学反应的影响。我们发现，与自然月经周期的参与者相比，服用 OC 的参与者在急性交感神经激活期间表现出矛盾性血管舒张；值得注意的是，组间差异不受月经/药丸阶段的影响。
