Miller J R, Hawkins D J, Wells J N
J Pharmacol Exp Ther. 1986 Oct;239(1):38-42.
We have studied the effects of activators of the Ca++- and phospholipid-dependent enzyme protein kinase C on isometric tension development by both intact and skinned coronary artery strips. The intact strips contracted upon incubation with 12-O-tetradecanoylphorbol-13-acetate. 12-O-tetradecanoylphorbol-13-acetate produced a leftward shift in the concentration-response relationship for contraction of the tissues by K+, histamine and norepinephrine. Phorbol-12,13-dibutyrate elicited contraction of detergent-skinned artery strips when the free Ca++ concentration in the bathing media was 0.1 microM or greater. This effect was diminished greatly in the presence of polymyxin B, a putative inhibitor of protein kinase C. Phorbol-12,13-dibutyrate shifted the Ca++ concentration-tension response relationship for the skinned tissue to the left. These results are consistent with a role for protein kinase C in regulating the contractile responses of coronary arterial smooth muscle to a variety of stimuli, at least in part by increasing the sensitivity of the contractile apparatus to Ca++.
我们研究了钙离子和磷脂依赖性酶蛋白激酶C的激活剂对完整和去皮冠状动脉条等长张力发展的影响。完整的冠状动脉条与12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯一起孵育时会收缩。12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯使组织对钾离子、组胺和去甲肾上腺素收缩的浓度 - 反应关系向左移位。当浴液中游离钙离子浓度为0.1微摩尔或更高时，佛波醇 - 12,13 - 二丁酸酯能引起去垢剂处理的动脉条收缩。在假定的蛋白激酶C抑制剂多粘菌素B存在的情况下，这种效应会大大减弱。佛波醇 - 12,13 - 二丁酸酯使去皮组织的钙离子浓度 - 张力反应关系向左移位。这些结果表明蛋白激酶C在调节冠状动脉平滑肌对多种刺激的收缩反应中起作用，至少部分是通过增加收缩装置对钙离子的敏感性来实现的。
