Analysis of effects of Ca-antagonists in pathophysiological models

在病理模型条件下对钙拮抗剂的作用机制进行了分析。(1) SHR大鼠与WKY大鼠主动脉Ca通道数量无显著差异，即使在SHR中高血压已建立。(2)研究了地尔硫卓及其季衍生物在正常和不同pH条件下对离体心室肌细胞ICa(L)的影响。我们发现地尔硫卓在膜外起作用。(3)在豚鼠心室肌中研究细胞外钾离子浓度升高对钙拮抗剂负性肌力的影响。我们发现，钙拮抗剂的不同效果可以用它们对ICa的使用依赖性阻断效应的电压依赖性来解释(L)。

An analysis of the mechanism of Ca antagonists was studied in the pathological model condition.(1) The number of Ca channels in aortas of SHR and WKY rats are not significantly different, even when hypertension is established in SHR.(2) The effects of diltiazem and its quaternary derivatives on ICa(L) in isolated ventricular myocytes were studied in normal and different pH conditions. We found that diltiazem acts from outside of the membrane.(3) The effects of elevation of extracellular K+ concentration on the negative inotropic potencies of Ca antagonists were investigated in guinea-pig ventricular muscle. We found that the differential effects of the Ca antagonists are explained by the differences in voltage dependency of their use-dependent blocking effects on ICa(L).