Does the pressor response to ischemic exercise improve blood flow to contracting muscles in humans?
Does the pressor response to ischemic exercise improve blood flow to contracting muscles in humans?
复制标题
对缺血性运动的升压反应是否会改善人类收缩肌肉的血流？
DOI：
10.1152/jappl.1991.71.4.1496
复制
发表时间：
1991
影响因子：
3.3
通讯作者：
Michael J. Joyner
中科院分区：
文献类型：
--
作者：
Michael J. Joyner
这项研究的目的是在人类中确定1)当节律性收缩肌肉的灌流压力降低时发生的反射性升压反应的增益，以及2)升压反应是否改善了收缩肌肉的血流量。6名正常受试者进行轻度、中度和重度前臂收缩(30次/分钟)，将前臂封闭在有机玻璃盒子中。箱内压力每分钟增加10毫米汞柱至50毫米汞柱，以降低前臂动脉系统的跨壁压。连续测量平均动脉压(MAP)。在轻度运动中，直到箱压达到50毫米汞柱时，MAP才出现反射性增加。在中等强度和大强度运动中，MAP开始升高，而箱压仅增加10-20毫米汞柱。这种增加的斜率是每10毫米汞箱压力3.5-3.9毫米汞柱(大约是狗的60%)。在一项针对六名受试者的进一步研究中，研究人员插入一条深静脉，引流前臂活跃肌肉，并测量深静脉血氧饱和度，以评估在高强度有节奏的运动中，箱压升高50毫米汞以及随后的MAP反射增加如何改变流向收缩肌肉的血流量。盒子压力的增加使前臂收缩肌肉的血流量减少了20%-25%，随后MAP增加了19毫米汞，但似乎并没有改善活跃肌肉的血流灌注。这一发现是出乎意料的，因为对狗的研究表明，在限制肌肉血流的情况下，有节奏的运动所产生的升压反应可以改善活跃肌肉的灌注量。
The purpose of this study was to determine in humans 1) the gain for the reflex pressor response that occurs when perfusion pressure to rhythmically contracting muscles is reduced and 2) whether the pressor response improves blood flow to the contracting muscles. Six normal subjects performed light, moderate, and heavy rhythmic forearm contractions (30/min) with the forearm enclosed in a Plexiglas box. Pressure in the box was increased 10 mmHg each minute up to 50 mmHg to reduce transmural pressure in the arterial system of the forearm. Mean arterial pressure (MAP) was measured continuously. During light exercise no reflex increase in MAP occurred until box pressure was 50 mmHg. During moderate and heavy exercise MAP began to increase with only 10- to 20-mmHg increases in box pressure. The slope of this increase was 3.5-3.9 mmHg per 10 mmHg of box pressure (approximately 60% of that in dogs). In a further study on six subjects a deep vein draining the active forearm muscles was cannulated and deep venous O2 saturation measured to assess how a 50-mmHg increase in box pressure and subsequent reflex increase in MAP altered blood flow to the contracting muscles during heavy rhythmic exercise. The increase in box pressure reduced blood flow to contracting forearm muscles by 20-25% and was followed by a 19-mmHg increase in MAP that did not appear to improve perfusion of the active muscles. This finding was unexpected, because studies in dogs suggest that the pressor response to rhythmic exercise with restricted muscle blood flow can improve perfusion of the active muscles.(ABSTRACT TRUNCATED AT 250 WORDS)