Is the muscle metaboreflex important in control of blood flow to ischemic active skeletal muscle in dogs?
Is the muscle metaboreflex important in control of blood flow to ischemic active skeletal muscle in dogs?
复制标题
肌肉代谢反射对于控制狗缺血性活动骨骼肌的血流很重要吗？
DOI：
10.1152/ajpheart.1995.268.3.h980
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Sheriff,DD
中科院分区：
文献类型：
--
作者：
O'Leary,DS;Sheriff,DD
活动性骨骼肌的缺血诱导交感神经活动、心率、心输出量和动脉压的反射性增加，称为肌肉代谢反射。这种升压反应是否对缺血性活动性骨骼肌的血流调节有重要作用还不清楚。如果在缺血肌肉中没有显著的血管收缩的情况下实现升压反应，则动脉压的这种增加将起到改善肌肉血流量的作用。狗进行轻度（3.2公里/小时，0%级）和中度（6.4公里/小时，10%级）的工作负荷的跑步机运动。在每个工作负荷期间，通过植入在终末主动脉上的血管封堵器的分级部分充气来增加后肢（Rh）中的血流阻力。基于终末主动脉血流量（TAQ）的稳态变化，计算肌肉代谢反射（Gcl）的闭环增益。如果没有发生升压反应，则TAQ应与总Rh（由于部分血管闭塞和后肢血管阻力引起的阻力之和）的增加成比例地降低;即，不会发生后肢血流的反射恢复。然而，随着全身动脉压的反射性增加，TAQ可能会升高到Rh增加的基础上预测的水平以上。我们观察到，在轻度运动期间，随着Rh的初始增加，Gcl与零无显著差异（P > 0.05）。（250字处删节）
Ischemia of active skeletal muscle induces a reflex increase in sympathetic activity, heart rate, cardiac output, and arterial pressure, termed the muscle metaboreflex. Whether this pressor response contributes importantly in the regulation of blood flow to the ischemic active skeletal muscle is not well understood. If the pressor response is achieved without substantial vasoconstriction in the ischemic muscle, this increase in arterial pressure would act to improve muscle blood flow. Dogs performed treadmill exercise at mild (3.2 km/h, 0% grade) and moderate (6.4 km/h, 10% grade) workloads. During each workload, resistance to blood flow in the hindlimbs (Rh) was increased via graded partial inflation of a vascular occluder implanted on the terminal aorta. The closed-loop gain of the muscle metaboreflex (Gcl) was calculated, based on the steady-state changes in terminal aortic blood flow (TAQ). If no pressor response occurred, then TAQ should decrease in proportion to the increase in total Rh (the sum of resistance due to partial vascular occlusion and hindlimb vascular resistance); i.e., no reflex restoration of hindlimb blood flow would occur. However, with a reflex increase in systemic arterial pressure, TAQ could rise above the level predicted on the basis of the increase in Rh. We observed that with the initial increase in Rh during mild exercise, Gcl was not significantly different from zero (P > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)