Baroreflex attenuates pressor response to graded muscle ischemia in exercising dogs.
Baroreflex attenuates pressor response to graded muscle ischemia in exercising dogs.
复制标题
压力反射减弱运动犬对分级肌肉缺血的升压反应。
DOI：
10.1152/ajpheart.1990.258.2.h305
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Rowell,LB
中科院分区：
文献类型：
--
作者：
Sheriff,DD;O'Leary,DS;Scher,AM;Rowell,LB
在以2英里/小时的速度运动的狗的后肢灌注逐渐减少（0%等级），通过所谓的“肌肉化学反射”引起反射性加压反应。为了确定动脉压力感受器反射在多大程度上反对肌肉的化学反射，我们在动脉压力感受器慢性手术去神经前后诱导了肌肉缺血的压力反应。在动脉压力感受器完好的情况下，肌肉化学反射显示出一个阈值，超过该阈值，后肢灌注压每降低1 mmHg，全身压升高约3 mmHg。动脉压力感受器去神经支配约使升压反应增加一倍，即后肢灌注压每下降1 mmHg，全身压升高约6 mmHg，而阈值没有改变。我们得出结论，在轻度动态运动中，动脉压力反射与后肢灌注逐渐减少的压力反应相反，减少了大约50%。当没有动脉压力反射时，肌肉化学反射的增益（全身压力变化与后肢灌注压力变化的比值）约为-6；因此，这种反射可以纠正85%由部分血管闭塞引起的肌肉灌注压下降。
Graded reductions in hindlimb perfusion in dogs exercising at 2 miles/h (0% grade) elicited reflex pressor responses by what is referred to as the “muscle chemoreflex.” To determine the extent to which arterial baroreceptor reflexes oppose the muscle chemoreflex, we elicited pressor responses to muscle ischemia before and after chronic surgical denervation of the arterial baroreceptors. The muscle chemoreflex showed a threshold beyond which systemic pressure rose approximately 3 mmHg for each 1-mmHg decrease in hindlimb perfusion pressure when the arterial baroreceptors were intact. Arterial baroreceptor denervation approximately doubled the pressor responses, i.e., systemic pressure rose by approximately 6 mmHg for each 1-mmHg fall in hindlimb perfusion pressure, without alteration in threshold. We conclude that during mild dynamic exercise, the arterial baroreflexes oppose the pressor response to graded reductions in hindlimb perfusion, reducing it by approximately 50%. When unopposed by the arterial baroreflexes the muscle chemoreflex exhibits a gain (ratio of change in systemic pressure to change in hindlimb perfusion pressure) of approximately -6; thus this reflex can correct by 85% the decrease in muscle perfusion pressure caused by partial vascular occlusion.