Dihydropyridine calcium agonists selectively enhance resistance artery myogenic tone.
Dihydropyridine calcium agonists selectively enhance resistance artery myogenic tone.
复制标题
二氢吡啶钙激动剂选择性增强阻力动脉肌源张力。
DOI：
10.1016/0014-2999(86)90052-x
复制
发表时间：
1986
影响因子：
5
通讯作者：
Bevan,JA
中科院分区：
文献类型：
--
作者：
Hwa,JJ;Bevan,JA
Upon stretch in normal physiological salt solution (PSS), two dihydropyridine (DHP) Ca2+agonists (Bay k 8644 and CGP 28392) enhanced the level of stretch-dependent myogenic tone in rabbit ear resistance arteries. This potentiating effect was not blocked by phenoxybenzamine (1 μM) and was Ca2+-dependent. Bay k 8644 was more potent than CGP 28392. These agonists had a smaller potentiating effect on K+(20 mM)-induced contraction, and had little effect in the presence of high K+(50–134 mM) PSS. Stretch-dependent myogenic tone is resistant to the inhibitory effect of nimodipine, a selective DHP Ca2+antagonist which inhibited K+(50 mM)-induced contraction in the nanomolar range. The potentiating effects of Bay k 8644 and CGP 28392 on myogenic tone were reversed by nimodipine. Our data suggest that (1) DHP Ca2+agonists selectively enhance myogenic tone by a mechanism that is antagonized by nimodipine, although physiological activation of myogenic tone is nimodipine insensitive, and (2) the calcium related mechanisms of myogenic tone are distinct from those for high K+depolarization-induced tone.
