Department of Exercise Science, Health and Physical Education, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
Auton Neurosci. 2010 Apr 19;154(1-2):89-93. doi: 10.1016/j.autneu.2009.11.002. Epub 2009 Nov 24.
The menstrual cycle has been reported to alter mean arterial pressure (MAP), but not muscle sympathetic nerve activity (MSNA), during vestibular activation. Specifically, MAP responses to head-down rotation (HDR) are augmented during the mid-luteal (ML) phase compared to the early follicular (EF) phase in young, eumenorrheic women. The purpose of the present study was to determine if the menstrual cycle influences vestibular-mediated changes in limb blood flow. MSNA, MAP, heart rate, and limb blood flow responses to HDR were measured in 12 healthy women. Resting MSNA, MAP, heart rate, forearm blood flow and calf blood flow were not altered by the menstrual cycle. HDR elicited similar increases in MSNA during the EF (Delta3+/-1 bursts/min; P<0.05) and ML (Delta2+/-1 bursts/min; P<0.05) phase, but only increased MAP during the ML phase (Delta4+/-2 mmHg; P<0.05). HDR did not change heart rate during either the EF or ML phase. HDR elicited similar increases in calf vascular resistance during the EF (Delta6+/-2 mmHg/mL/100 mL/min; P<0.05) and ML (Delta7+/-2 mmHg/mL/100mL/min; P<0.05) phases of the menstrual cycle. In contrast, HDR increased forearm vascular resistance during the ML phase (Delta4+/-2 mmHg/mL/100mL/min; P<0.05), but not the EF phase (Delta0+/-2 mmHg/mL/100mL/min). These findings suggest an increased transduction of sympathetic nerve activity into forearm vascular resistance during the ML phase, and reveal the first recorded divergent vascular response to vestibular excitation in human limbs.
月经周期被报道会改变平均动脉压（MAP），但不会改变前庭激活时的肌肉交感神经活动（MSNA）。具体来说，与卵泡早期（EF）相比，年轻、月经正常的女性在下一个黄体中期（ML），头低位旋转（HDR）的 MAP 反应增强。本研究的目的是确定月经周期是否会影响前庭介导的肢体血流变化。12 名健康女性接受了 HDR 引起的 MSNA、MAP、心率和肢体血流反应的测量。静息 MSNA、MAP、心率、前臂血流和小腿血流不受月经周期影响。EF 期（Delta3+/-1 爆发/分钟；P<0.05）和 ML 期（Delta2+/-1 爆发/分钟；P<0.05）HDR 引起的 MSNA 相似增加，但仅在 ML 期增加 MAP（Delta4+/-2 mmHg；P<0.05）。HDR 既不改变 EF 期也不改变 ML 期的心率。EF 期（Delta6+/-2 mmHg/mL/100 mL/min；P<0.05）和 ML 期（Delta7+/-2 mmHg/mL/100mL/min；P<0.05）HDR 引起的小腿血管阻力相似增加。相比之下，HDR 在 ML 期增加前臂血管阻力（Delta4+/-2 mmHg/mL/100mL/min；P<0.05），而在 EF 期则没有增加（Delta0+/-2 mmHg/mL/100mL/min）。这些发现表明，在 ML 期，交感神经活动向前臂血管阻力的传递增加，并揭示了人类四肢对前庭刺激的第一个记录到的血管反应差异。
