Human Cardiovascular Physiology Laboratory, Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
Am J Physiol Regul Integr Comp Physiol. 2024 Dec 1;327(6):R528-R533. doi: 10.1152/ajpregu.00199.2024. Epub 2024 Oct 7.
A burst of muscle sympathetic nerve activity (MSNA) induces vasoconstriction that transiently reduces regional vascular conductance and increases systemic blood pressure (BP) over the subsequent 4-8 cardiac cycles. These responses are termed sympathetic neurovascular transduction and sympathetic transduction of BP, respectively. Sympathetic transduction of BP is commonly calculated and interpreted as a proxy measure for regional sympathetic neurovascular transduction despite the systemic nature of BP regulation. The present analysis tested whether the peak change in signal-averaged sympathetic transduction of BP was correlated to the change in regional sympathetic vascular transduction at rest. Fourteen adults (5 females, 23 ± 3 yr) arrived at the laboratory, ate a standardized meal, and rested for 90-120 min. MSNA (fibular nerve microneurography), heart rate (electrocardiography), beat-to-beat BP (finger photoplethysmography), and superficial femoral artery blood flow (Doppler ultrasound) were obtained continuously for 10 min in the supine position. Femoral vascular conductance (FVC) was calculated as blood flow divided by mean arterial BP. The peak change in diastolic BP following a burst of MSNA was correlated to the corresponding nadir change in femoral vascular conductance ( = -0.58 [-0.07 to -0.85], = 0.03) and superficial femoral artery blood flow ( = -0.54 [-0.17 to -0.83], = 0.04). The nadir change in diastolic BP in cardiac cycles not following an MSNA burst was correlated to the peak change in femoral vascular conductance ( = -0.42 [-0.83 to 0.00], = 0.05), but not superficial femoral artery blood flow ( = 0.41 [-0.77 to 0.15], = 0.14). In conclusion, more commonly assessed sympathetic transduction of BP provides moderate insight into regional sympathetic neurovascular transduction. The majority of studies have used signal-averaged sympathetic transduction of blood pressure as a generalized measure of transduction. In this analysis, we show that sympathetic transduction of blood pressure and regional sympathetic vascular transduction were moderately correlated in healthy adults at rest. The moderate strength of this relationship highlights potential differences between regional and systemic assessments of sympathetic transduction and suggests that future work should choose the transduction measure best aligned with the research question.
肌肉交感神经活动（MSNA）的爆发会引起血管收缩，在随后的 4-8 个心动周期中，会暂时降低局部血管传导率并增加全身血压（BP）。这些反应分别称为交感神经血管转导和 BP 的交感转导。尽管 BP 调节具有系统性，但 BP 的交感转导通常被计算和解释为局部交感神经血管转导的替代测量。本分析测试了 BP 的信号平均交感神经转导的峰值变化是否与休息时局部交感血管转导的变化相关。14 名成年人（女性 5 名，23±3 岁）到达实验室，吃了标准餐，休息 90-120 分钟。MSNA（腓肠神经微神经记录）、心率（心电图）、逐搏 BP（手指光电容积描记法）和股浅动脉血流（多普勒超声）在仰卧位连续 10 分钟获得。股血管传导率（FVC）计算为血流除以平均动脉 BP。MSNA 爆发后舒张压的峰值变化与股血管传导率的相应最低值变化相关（ = -0.58[-0.07 至 -0.85]， = 0.03）和股浅动脉血流（ = -0.54[-0.17 至 -0.83]， = 0.04）。MSNA 爆发后不跟随的心动周期中的舒张压最低值与股血管传导率的峰值变化相关（ = -0.42[-0.83 至 0.00]， = 0.05），但与股浅动脉血流无关（ = 0.41[-0.77 至 0.15]， = 0.14）。总之，更常见的评估 BP 的交感神经转导为局部交感神经血管转导提供了适度的见解。大多数研究使用平均信号的 BP 交感神经转导作为转导的一般衡量标准。在本分析中，我们表明，健康成年人在休息时，BP 的交感神经转导与局部交感血管转导中度相关。这种关系的中等强度突出了局部和系统评估交感神经转导之间的潜在差异，并表明未来的工作应该选择与研究问题最匹配的转导测量。
