O'Hagan K P, Bell L B, Mittelstadt S W, Clifford P S
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee.
J Appl Physiol (1985). 1993 May;74(5):2099-104. doi: 10.1152/jappl.1993.74.5.2099.
Renal sympathetic nerve activity (RSNA) increases abruptly at the onset of treadmill exercise in conscious rabbits. This study investigated whether the rise in RSNA is related to the intensity of the exercise and whether an elevated level of RSNA is maintained during submaximal exercise. RSNA, arterial blood pressure (BP), and heart rate (HR) were recorded in 10 New Zealand White rabbits during two treadmill exercise protocols at 0% grade: 7 m/min for 5 min and 12 m/min for 2 min. Peak levels of RSNA were observed in the first 10 s of exercise at 7 and 12 m/min. Through 2 min of exercise, the rise in RSNA was greater (P < 0.05) at 12 m/min (delta 83 +/- 22%) compared with 7 m/min (delta 49 +/- 8%). At 7 m/min, HR and BP reached steady-state levels during the 2nd min of exercise. RSNA remained elevated at delta 43 +/- 10 to delta 54 +/- 13% over resting levels as exercise continued from the 2nd through the 5th min of exercise (P < 0.05). These data demonstrate that the RSNA response to exercise is intensity related and suggest that RSNA remains elevated and thus may contribute to the control of renal blood flow during submaximal dynamic exercise.
在清醒的兔子进行跑步机运动开始时，肾交感神经活动（RSNA）会突然增加。本研究调查了RSNA的升高是否与运动强度有关，以及在次最大运动期间RSNA是否维持在升高水平。在10只新西兰白兔进行0%坡度的两种跑步机运动方案期间记录RSNA、动脉血压（BP）和心率（HR）：7米/分钟持续5分钟和12米/分钟持续2分钟。在7米/分钟和12米/分钟运动的前10秒观察到RSNA的峰值水平。在运动2分钟时，与7米/分钟（增量49±8%）相比，12米/分钟时RSNA的升高幅度更大（P<0.05）（增量83±22%）。在7米/分钟时，HR和BP在运动第2分钟时达到稳态水平。从运动第2分钟持续到第5分钟时，RSNA比静息水平持续升高43±10%至54±13%（P<0.05）。这些数据表明，RSNA对运动的反应与强度有关，并提示在次最大动态运动期间RSNA维持升高，因此可能有助于肾血流的控制。
