ROLE OF ARTERIAL BARORECEPTORS IN MEDIATING CARDIOVASCULAR-RESPONSE TO EXERCISE
ROLE OF ARTERIAL BARORECEPTORS IN MEDIATING CARDIOVASCULAR-RESPONSE TO EXERCISE
复制标题
DOI：
10.1152/ajplegacy.1976.230.1.85
复制
发表时间：
1976-01-01
影响因子：
--
通讯作者：
BRAUNWALD, E
中科院分区：
文献类型：
--
作者：
MCRITCHIE, RJ;VATNER, SF;BRAUNWALD, E
通过比较非拴系清醒犬和完全动脉压力感受器失神经(TABD)犬的主动脉压和心输出量的反应，研究了主要动脉压力感受器反射在运动心血管反应中的作用。中等强度的运动(12英里/小时)使正常狗的心输出量从每分钟111+/-17毫升/公斤增加，心率从101+/-5次/分钟增加到265+/-8次/分钟，总外周阻力从每分钟0.039+/-0.003毫米汞/毫升降低到0.015+/-0.002毫米汞/毫升。患有TABD的狗以非常相似的方式做出反应：运动将心输出量从每分钟119+/-8增加到356/-23毫升/公斤，心率从122+/-7增加到256+/-5次/分钟，总外周阻力从每分钟0.042+/-0.005下降到+/-0.015+/-0.001毫米汞/毫升。研究人员还检测了正常动物在静息和运动时对静脉注射甲氧胺的反射性心率反应。甲氧胺在安静状态下会引起严重的心动过缓，但在运动时会引起轻微的心动过缓。这些结果表明，在剧烈运动中，动脉压力感受器反射通常是关闭的，因此不会显著改变运动对心血管的反应。
The role played by the major arterial baroreceptor reflexes in the cardiovascular response to exercise was examined by comparing the responses of untethered conscious dogs instrumented for the measurement of aortic pressure and cardiac output with those of dogs with total arterial barorecptor denervation (TABD). Moderately severe levels of exercise (12 mph) in intact dogs increased cardiac output from 111 +/- 17 ml/kg per min, increased heart rate from 101 +/- 5 to 265 +/- 8 beats/min, and reduced total peripheral resistance from 0.039 +/- 0.003 to 0.015 +/- 0.002 mmHg/ml per min. Dogs with TABD responded in a very similar fashion; exercise increased cardiac output from 119 +/- 8 to 356 /+- 23 ml/kg per min, increased heart rate from 122 +/- 7 to 256 +/- 5 beats/min, and decreased total peripheral resistance from 0.042 +/- 0.005 to +/- 0.015 +/- 0.001 mmHg/ml per min. The reflex heart rate responses to intravenous bolus doses of methoxamine were also examined in intact animals, both at rest and during exercise. Methoxamine caused striking bradycardia at rest, but little bradycardia during exercise. These results suggest that the arterial baroreceptor reflex is normally turned off during severe exercise and thus does not modify significantly the cardiovascular response to exercise.