Rate-limiting steps in the tension development of freeze-glycerinated vascular smooth muscle.
Rate-limiting steps in the tension development of freeze-glycerinated vascular smooth muscle.
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DOI：
10.1085/jgp.79.3.437
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发表时间：
1982-03
期刊：
影响因子：
--
通讯作者：
Peterson JW 3rd
中科院分区：
文献类型：
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作者：
Peterson JW 3rd
提出了一种“剥皮”动脉平滑肌的方法，该方法在微摩尔Ca++和毫摩尔Mg-ATP存在的情况下，通常产生最大生理张力的60-80%，同时基本上保留天然蛋白质含量。使用“CA跳变”的方法，可以使皮肤动脉中CA ++激活的张力发展的时间过程与完整动脉中的张力发展速度相同，但不会更快。在皮肤动脉中，激活游离[ca++]并不会实质性地改变张力发展接近游离[ca++]达到的最终稳定张力的速度（[ca++]下降10倍，但速度下降不到25%）。这些观察结果表明，动脉平滑肌等长张力发展的限速步骤并不直接依赖于Ca++。
A method for "skinning" arterial smooth muscle is presented which yields isometric tension development typically 60-80% of maximum physiological tension in the presence of micromolar Ca++ and millimolar Mg-ATP, while retaining essentially the native protein content. Using the methods of "CA jump," the time-course of Ca++-activated tension development in the skinned artery can be made identical to, but not faster than, the rate of tension development in the intact artery. In the skinned artery, activating free [Ca++] does not substantially alter the rate at which tension development approaches the final steady tension attained at that free [Ca++] (less than 25% decline in speed for a 10-fold decrease in [Ca++]). These observations are taken to mean that the rate-limiting step in isometric tension development in arterial smooth muscle does not depend directly on Ca++.