Direct Effects of Anesthertics and Vasoconstrictors on Contraction in Aorta Smooth Muscle of Spontaneously Hypertensive Rats

点击翻译按钮获取中文摘要

The aim of this study is to clarify the direct effects of a variety of anesthetics and vasoconstrictors on contraction and intracellular CaィイD12+ィエD1 mobilization in aorta smooth muscle of spontaneously hypertensive rats. Particularly, dental local anesthetics contains high concentration with epinephrine. Furthermore, we know dental patients with essential hypertension treated with nonselective β adorenoceptor blocking agents may show remarkable increase in blood pressure after administration of dental local anesthetics containing 1/80000 epinephrine. The hemodynamic changes should occur as a net result due to interaction between epinephrine with β adorenoceptor blocking agents. We investigated the effects of epinephrine alone or the combination of epinephrine and nonselective β adorenoceptor blocking agents, propranolol, on isometric tension of spontaneously hypertensive rat(SHR) aorta smooth muscle and intracellular calcium level ( [CaィイD12+ィエD1] i ) by the fura-2/AM simultaneously, and compared with those of normotensive Wister Kyoto rat(WKY).The results were obtained as follows ;1. In WKY, the increases in tension and [ CaィイD12+ィエD1 ] i induced by 10ィイD1-6ィエD1 M epinephrine were less than those by 60 mM KCl.2. In WKY, the tension induced by the combination of epinephrine and propranolol was significantly increased more than that by epinephrine alone, but there were no differences between them of [ CaィイD12+ィエD1 ] i.3. In SHR, the increase in tension induced by epinephrine was larger than that in WKY, but there were no differences between them of [ CaィイD12+ィエD1 ] i. By the combination of epinephrine and propranolol, [ CaィイD12+ィエD1 ] i was increased more than that by epinephrine alone, but the tension was maintained at the same level as that induced by epinephrine alone.