Regulation of Calcium Entry in Cerebral Arteries

小动脉控制着血液流向各个器官。这些动脉通常是收缩的，它们根据血液的需要扩张或收缩。大脑中的动脉对血液流动有特殊的要求；即使血压发生变化，它们也必须维持血液流动。钙离子（Ca2+）在动脉的狭窄和开放中起着关键作用。动脉壁肌肉细胞内的Ca2+离子导致肌肉细胞收缩，从而导致血管狭窄。我们研究Ca2+进入这些肌肉细胞的机制。Ca2+通过特殊的蛋白质进入平滑肌，这些蛋白质通过分离细胞内外的膜形成毛孔。这些毛孔被称为“钙通道”，是一类主要用于治疗高血压、心绞痛和中风的心血管药物“钙通道阻滞剂”的靶点。拟议中的项目将检查动脉中调节大脑血液流动的“钙通道”的特性。这应该是同类研究中的第一次，并且应该为理解一些最重要的动脉的直径是如何调节的提供重要的信息。这项研究是通过新技术分离小动脉和单个平滑肌的遗传菌株WKY大鼠。老鼠被麻醉并迅速杀死。然后迅速切除动脉。所有的实验都是在分离的动脉或从这些动脉中分离出的单个平滑肌细胞上进行的。这些研究应该是同类研究中的第一个，并且应该为理解强直性、自动调节动脉中钙进入的调节提供必要的基础。//

Small arteries control blood flow to various organs. These arteries are normally contracted from which they dilate or constrict depending on the need for blood. The arteries in the brain have a special requirement for blood flow; they must maintain blood flow even when the blood pressure changes. Calcium (Ca2+) ions play a critical role in the narrowing and opening of arteries. Ca2+ ions inside the muscle cells in the wall of the arteries cause the muscle cells to contract and consequently cause blood vessels to narrow. We study the mechanism by which Ca2+ enters these muscle cells. Ca2+ enters the smooth muscle through specialized proteins that form pores through membrane that separate the outside of the cell from the inside. These pores are called "calcium channels" and are the targets of a major class of cardiovascular drugs called "calcium channel blockers" that are used to treat hypertension, angina, and stroke. The proposed project will examine the properties of "calcium channels" in arteries that regulate blood flow in the brain. This should be the first study of its kind and should provide vital information to the understanding of how the diameter of some of the most important arteries is regulated. This study has been made possible by new techniques to isolate small arteries and single smooth muscle of genetic strain of rats called WKY. The rats are anesthetized and rapidly killed. The arteries are then rapidly removed. All experiments are done on the isolated arteries or single smooth muscle cells isolated from these arteries. These studies should be the first of their kind and should provide a foundation essential for understanding the regulation of Ca entry in tonic, autoregulating arteries. //