Sutudy of vascular reactions in response to hemodynamic factors assessed by stretch activation

点击翻译按钮获取中文摘要

Cerebral and coronary arteries are extremely sensitive to hemodynamic factors, i.e., biomichacal stimule, including blood pressure and blood flow. I have investigated the ca^<2+>-signaling mechanisms of mechanical reception in the cardiovascular system from the following point of view, and as a leader i have promoted the progress of this relatively underdeveloped research field. I have regarded the myogenic contractile reaction of blood vessels in response to stretch of vascular wall or an increase in intraluminal pressure as a kind of cellular/intracellular and Ca^<2+> signaling ; and 3) the cross-bridge property of contractile elements. I could have showed interesting results as follows which will promise the future progress in the research. I have found that membrane fluidity strongly affects the sensitivity of a mechano-receptor site, and an amiloride-sensitive component, a possible stretch-activated channel, may play a role in the genesis of myogenic activity. In addition, the biomechanical stimulus augmented the activity of phospholipase C, production of inositol trisphosphate, and increase in cytosolic Ca^<2+> concentration, which indicates a possible role of GTP-binging proteins coupled with this enxyme in the transformation of mechanical stimulus to cellular signalings. Moreover, myogenic activity is found to be in-between the contraction produced by phorbol esters and high K^+ depolarizing stimulus in the property of cross-bridge cycling. These results suggest that vascular reaction in response to biomechanical stimuli is mediated through a novel mechanisum of cellular signaling.