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Assessment of the role of flow induced dilation by focusing on delay time between increase in flow velocity and vasodilation, and of arteriolar location among the different muscles

通过关注流速增加和血管舒张之间的延迟时间以及不同肌肉之间的小动脉位置来评估流量引起的扩张的作用

基本信息

批准号：
14580011
负责人：
MAEDA Junichi
金额：
$ 1.73万
依托单位：
Miyagi University of Education
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

A parallel occlusion of one of the branch arterioles induces vasodilation in the opposite unoccluded branch. Increases in flow and wall share rate in the unoccluded branch by the parallel occlusion has been thought to be one of the primary causes of vasodilation. This dilation induced by the parallel occlusion has been referred to as evidence that flow-induced dilation plays a significant role in diameter control on the microvascular network. However, there are some studies which argue that mechanisms other than the flow induced dilation is involved in the vasodilation observed in microcirculation during parallel occlusion. The purpose of this study is readdressing the role of flow induced dilation during parallel occlusion by focusing on delay times between increase in flow velocity and vasodilation during parallel occlusion. The differences of flow induced dilation and myogenic responses among different skeletal muscles are also analyzed.In 23 of the 40 occlusions, diameter of unoccluded arterioles dilated immediately after onset of parallel occlusion with increases in diameter (18.1 +/-4.51 % of control), WSR (65.7 +/-8.91 %), velocity (80.5 +/-8.47 % of control) and flow (153.4 +/-23.2 % of control). In the rest of the 17 occlusions, arterioles dilated with 8.8 +/-1.1 sec of delay time after the onset of occlusion. In these cases, the increases in diameter (22.1 +/-2.51 %), WSR (117.8 +/-22.8 %), velocity (119.1 +/-17.8 %) and flow (241.6 +/-26.8 %) from the control were significantly higher than the increase in the values observed without delay time. From these results, we concluded that the dilation with or without delay time from onset of the occlusion is functionally different. Thus, delay. time is a crucial index to identify the flow induced dilation. We also suggest that location of the arterioles affects the response of myogenic and flow induced vascular activities to changes in flow velocity and transmural pressure.

其中一条分支小动脉的平行闭塞引起相对未闭塞的分支的血管舒张。平行闭塞引起的未闭塞分支中的流量和壁共享率的增加被认为是血管舒张的主要原因之一。这种由平行闭塞引起的扩张已经被认为是流动引起的扩张在微血管网络的直径控制中起重要作用的证据。然而，有一些研究认为，在平行闭塞期间，在微循环中观察到的血管舒张涉及除流动诱导的扩张之外的机制。本研究的目的是通过关注平行闭塞期间血流速度增加与血管舒张之间的延迟时间，重新探讨平行闭塞期间血流诱导扩张的作用。同时分析了不同骨骼肌的血流诱导性扩张和肌源性反应的差异，在40个闭塞中，有23个闭塞的未闭塞小动脉在平行闭塞开始后立即扩张，直径增加（对照的18.1 +/-4.51%）、WSR（65.7 +/-8.91%）、速度（对照的80.5 +/-8.47%）和流量（对照的153.4 +/-23.2%）。在其余17例闭塞中，小动脉在闭塞开始后扩张，延迟时间为8.8 ± 1.1秒。在这些情况下，直径（22.1 +/-2.51%）、WSR（117.8 +/-22.8%）、速度（119.1 +/-17.8%）和流量（241.6 +/-26.8%）相对于对照组的增加显著高于无延迟时间时观察到的值的增加。从这些结果中，我们得出结论，从闭塞开始有或没有延迟时间的扩张在功能上是不同的。因此，延迟。时间是鉴别血流诱导扩张的重要指标。我们还认为，小动脉的位置影响肌源性和流动引起的血管活动的流速和跨壁压的变化的反应。