平滑肌离子通道机制在模拟失重致血管适应性变化中的作用

发布时间：2018-01-02 00:25

本文关键词：平滑肌离子通道机制在模拟失重致血管适应性变化中的作用　出处：《第四军医大学》2005年博士论文　论文类型：学位论文

【摘要】：航天失重环境可使人体流体静压消失,从而使全身动脉血管系统跨壁压的分布以及血液分布均发生重大改变:上半身血压较地面1G直立体位时相对升高,脑血管处于持续的“高血压”状态;下半身血管则处于较1G直立时相对较低的“低血压”状态。本实验室近年首次系统阐明:模拟失重可引起大鼠脑动脉血管的收缩反应性上调及脑血管中膜肥厚、平滑肌细胞层数增多等结构性改变;而后身动脉则可引起收缩功能下调及中膜萎缩等重塑变化,并据此提出了“外周效应器机制假说”来解释航天飞行后的姿势性压力反射减弱和脑循环自体调节功能变化的机理。我们近年工作还发现模拟失重致血管区域特异性适应变化涉及血管组织局部肾素血管紧张素系统(local renin-angiotensin system,L-RAS)与血管平滑肌(vascular smooth muscle cell,VSMC)的离子通道机制。关于后者,我们前期工作已观察到短期(1周)与中期(4周)模拟失重大鼠后身动脉(隐
[Abstract]:Space weightlessness environment can make the hydrostatic pressure of human body disappear, thus make the blood distribution and blood pressure distribution of the systemic arterial vascular system change significantly: the blood pressure of the upper half body is higher than that of 1G standing position on the ground. The cerebral vessels are in a continuous state of "hypertension"; The lower hemispheres are in a relatively low "hypotension" state, which is lower than 1G when standing upright. For the first time in recent years, our laboratory has systematically stated that:. Simulated weightlessness can induce the contractile reactivity of cerebral artery and the thickening of cerebral mesenteric membrane in rats. The number of smooth muscle cell layers increased and other structural changes; Then the body artery could induce the remodeling changes such as down-regulation of systolic function and atrophy of medial membrane. Based on this, the hypothesis of peripheral effector mechanism was put forward. To explain the mechanism of postural baroreflex decrease and cerebral circulation autoregulation after spaceflight flight. We also found in recent years that the regional adaptation of simulated weightlessness is related to regional renin blood in vascular tissue. Tube tension system (. Local renin-angiotensin system. The ion channel mechanism between L-Ras and vascular smooth muscle cells (VSMC). We have observed that the posterior body artery (saphenous artery) of simulated weightlessness rats has been observed for a short period of 1 week and the middle stage for 4 weeks.
【学位授予单位】：第四军医大学
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R85

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