Edwards R, Trizna W
SmithKline Beecham Pharmaceuticals, King of Prussia, Pa.
Pharmacology. 1990;41(3):149-52. doi: 10.1159/000138711.
The effects of endothelin-1, -2 and -3 (ET-1, -2, -3) on lumen diameter of intracerebral arterioles isolated from rat brain were examined. All three ETs produced concentration-dependent decreases in lumen diameter with EC50 values of 0.7, 1.5 and 58 mmol/l for ET-1, ET-2 and ET-3, respectively. The calcium channel antagonist, nicardipine, had no significant effect on ET-1-induced contractions except at a concentration of 1 mumol/l which attenuated the maximum response to ET-1, but had no effect on the EC50 value. The potent vasoconstrictor action of ET on intracerebral arterioles suggest an important role for this peptide in the regulation of the cerebral microvasculature.
研究了内皮素-1、-2和-3（ET-1、-2、-3）对从大鼠脑部分离出的脑内小动脉管腔直径的影响。所有三种内皮素均使管腔直径呈浓度依赖性减小，ET-1、ET-2和ET-3的半数有效浓度（EC50）值分别为0.7、1.5和58 mmol/l。钙通道拮抗剂尼卡地平对ET-1诱导的收缩无显著影响，除非浓度为1 μmol/l时，此时它会减弱对ET-1的最大反应，但对EC50值无影响。ET对脑内小动脉的强效血管收缩作用表明该肽在脑微血管调节中起重要作用。
