Forder J, Scriabine A, Rasmussen H
J Pharmacol Exp Ther. 1985 Nov;235(2):267-73.
Isolated perfused rabbit ear arteries contract when treated with 12-O-tetradecanoylphorbol-13-acetate (TPA), an activator of the calcium-activated, phospholipid-dependent protein kinase or C-kinase. Under conditions where the calcium concentration in the perfusate is 1.5 mM and the potassium concentration is 4.8 mM, there is a latent period of 70 +/- 19 min (mean +/- S.E.M., n = 10) between TPA addition and the onset of the contractile response. Once initiated, the contractile response is progressive and sustained. When perfusion conditions are altered in such a way as to modify calcium flux across the plasma membrane (i.e., raising the extracellular calcium concentration to 2.5 mM Ca++, raising the extracellular potassium concentration to 10 mM, and/or preincubating the tissues in media containing 100 nM Bay K 8644, a potent calcium channel agonist), the latency period between TPA addition and initiation of the contractile response is significantly reduced (2.5 mM Ca++, 37 +/- 7 min; 10 mM K+ and 2.5 mM Ca++, 11 +/- 3 min; 100 nM Bay K 8644 and 1.5 mM Ca++, 20 +/- 7 min; 100 nM Bay K 8644 and 2.5 mM Ca2+, 8.5 +/- 1.7 min; 10 mM K+ and 100 nM Bay K 8644, 11 +/- 5 min). Likewise, the combination of 2.5 mM calcium, 100 nM Bay K 8644, and 3.3 microM ouabain results in a contractile response 4.5 +/- 2.0 min after TPA addition (means +/- S.E.M., n = 4). Control tissues (absence of TPA addition) run simultaneously show no contractile responses to the various Ca++ flux regulators even after 90 min of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)
当用12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）处理时，分离灌注的兔耳动脉会收缩，TPA是一种钙激活的、磷脂依赖性蛋白激酶或C激酶的激活剂。在灌注液中钙浓度为1.5 mM且钾浓度为4.8 mM的条件下，添加TPA与收缩反应开始之间存在70±19分钟（平均值±标准误，n = 10）的潜伏期。一旦开始，收缩反应是渐进性且持续的。当以改变跨质膜钙通量的方式改变灌注条件时（即，将细胞外钙浓度提高到2.5 mM Ca++，将细胞外钾浓度提高到10 mM，和/或在含有100 nM Bay K 8644（一种有效的钙通道激动剂）的培养基中预孵育组织），添加TPA与收缩反应开始之间的潜伏期显著缩短（2.5 mM Ca++时为37±7分钟；10 mM K+和2.5 mM Ca++时为11±3分钟；100 nM Bay K 8644和1.5 mM Ca++时为20±7分钟；100 nM Bay K 8644和2.5 mM Ca2+时为8.5±1.7分钟；10 mM K+和100 nM Bay K 8644时为11±5分钟）。同样，2.5 mM钙、100 nM Bay K 8644和3.3 microM哇巴因的组合在添加TPA后4.5±2.0分钟产生收缩反应（平均值±标准误，n = 4）。同时进行的对照组织（未添加TPA）即使在孵育90分钟后对各种Ca++通量调节剂也无收缩反应。（摘要截短至250字）
