Actions of a Phorbol Ester on Factors Regulating Contraction in Rabbit Mesenteric Artery
Actions of a Phorbol Ester on Factors Regulating Contraction in Rabbit Mesenteric Artery
复制标题
佛波酯对家兔肠系膜动脉收缩调节因子的作用
作者：
T. Fujiwara;T. Itoh;Y. Kubota;H. Kuriyama
本文观察了12-O-十四酰佛波醇-13-乙酸酯(TPA)对兔肠系膜动脉完整和皮肤肌肉组织等长张力、松弛试验测定的无负荷收缩速度(Vmax)和肌球蛋白轻链磷酸化(MLC20)的影响。在暴露于128 mM K+的完整肌肉中，Vmax在收缩时相分量达到峰值之前达到最大值，并随着随后紧张性收缩幅度的变化而成比例地减小。0.1TPA(0.1μM)增强强直肌的幅度大于时相收缩。在紧张期，TPA对收缩的Vmax和幅度的促进作用强于对MLC20的磷酸化。在皮肤肌肉中，钙离子(0.3−1.0μM)以剂量依赖的方式增加肌张力、Vmax和MLC20的磷酸化。上述三个参数中的任意两个参数之间的关系始终是线性的。TPA(0.1μM)和磷脂酰丝氨酸(5 0μ/ml)可时间依赖性地增加0.3~0.5μM Ca~(2+)引起的肌张力和Vmax。但在0.5μM Ca~(2+)中，TPA与磷脂酰丝氨酸的相互作用对MLC20的磷酸化影响不大。根据TPA的作用估计，蛋白激酶C可能通过依赖MLC20的磷酸化和其他调节过程来激活收缩蛋白。(流通研究1988；63：893-902)
The effects of 12-o-tetradecanoylphorbol-13-acetate (TPA) on isometric tension, unloaded shortening velocity determined using the slack test (Vmax), and phosphorylation of myosin light chain (MLC20) were investigated in intact and skinned muscle tissues of the rabbit mesenteric artery. In intact muscles exposed to 128 mM K+, the Vmax reached a maximum before the peak of the phasic component of contraction and reduced proportionally with changes in the amplitude of the subsequent tonic-contraction. TPA (0.1 μM) enhanced to a greater extent the amplitude of the tonic than the phasic contraction. During the tonic phase, TPA enhanced the Vmax and amplitude of the contraction more than the phosphorylation of MLC20. In skinned muscles, Ca2+ (0.3−1.0 μM) increased the force, Vmax and MLC20 phosphorylation, in a dose dependent manner. The relation between any two of the above three parameters was always linear. TPA (0.1 μM) with phosphatidylserine (50 μ/ml) time-dependently increased the force and Vmax observed with 0.3–0.5 μM Ca2+. The relation between the force and Vmax shifted in the direction of that observed in the presence of high Ca2+, but in 0.5 μM Ca2+, TPA with phosphatidylserine showed little change in the phosphorylation of MLC20. As estimated from the actions of TPA, protein kinase C may contribute to activation of contractile proteins through MLC20 phosphorylation dependent and other regulatory processes. (Circulation Research 1988;63:893-902)
登录
查看更多内容
Ca2 和肌球蛋白轻链磷酸化在平滑肌调节中的作用。
DOI：
10.1152/ajpcell.1982.242.1.c109
发表时间：
1982
期刊：
The American journal of physiology
影响因子：
--
作者：
Aksoy,MO;Murphy,RA;Kamm,KE
通讯作者：
Kamm,KE
Ca2 和 Mg2 对稳定磷酸化砂囊肌球蛋白的肌动球蛋白腺苷-5-三磷酸酶的影响。
影响因子：
2.9
作者：
Heaslip,RJ;Chacko,S
通讯作者：
Chacko,S
影响因子：
--
作者：
DRISKA, SP;AKSOY, MO;MURPHY, RA
通讯作者：
MURPHY, RA
卡巴胆碱诱导的牛气管平滑肌蛋白质磷酸化变化。
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Park,S;Rasmussen,H
通讯作者：
Rasmussen,H