内皮素在牛脑动脉中引发的血管收缩反应。

Vasoconstrictive responses elicited by endothelin in bovine cerebral arteries.

Encabo A, Ferrer M, Marín J, Villamor J, Balfagón G

Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, Madrid, Spain.

Gen Pharmacol. 1992 Mar;23(2):263-7. doi: 10.1016/0306-3623(92)90022-c.

Abstract

Endothelin (ET-1) induced concentration-dependent contractions, which were slowly developed in segments of bovine cerebral arteries. Furthermore, this agent produced tachyphylaxis. 2. The contractions evoked by ET-1 were markedly reduced in Ca-free medium containing 1 mM EGTA and by the Ca channel antagonist, nifedipine (1 microM), but increased by the Ca channel agonist, BAY K 8644 (10 nM). 3. The contractions caused by ET-1 were significantly reduced by the protein kinase C (PKC) inhibitor, staurosporine (1 and 10 nM). 4. These results indicate that ET-1 induced potent vasoconstrictive responses, probably mediated by PKC activation, which were mainly dependent on extracellular Ca; this Ca enters the smooth muscle cells via dihydropyridine sensitive Ca channels.

摘要

内皮素（ET-1）可引起浓度依赖性收缩，这种收缩在牛脑动脉节段中发展缓慢。此外，该药物会产生快速耐受性。2. 在含有1 mM乙二醇双四乙酸（EGTA）的无钙培养基中以及钙通道拮抗剂硝苯地平（1 microM）作用下，ET-1诱发的收缩明显减弱，但在钙通道激动剂BAY K 8644（10 nM）作用下收缩增强。3. 蛋白激酶C（PKC）抑制剂星形孢菌素（1和10 nM）可显著减弱ET-1引起的收缩。4. 这些结果表明，ET-1诱导产生强烈的血管收缩反应，可能是由PKC激活介导的，且主要依赖细胞外钙；这种钙通过二氢吡啶敏感的钙通道进入平滑肌细胞。