ACTIVATION OF THE CONTRACTILE MECHANISM IN STRIATED MUSCLE
ACTIVATION OF THE CONTRACTILE MECHANISM IN STRIATED MUSCLE
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DOI：
10.1111/j.1748-1716.1958.tb01608.x
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发表时间：
1958-01-01
期刊：
影响因子：
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通讯作者：
THESLEFF, S
中科院分区：
文献类型：
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作者：
AXELSSON, J;THESLEFF, S
1当青蛙的横纹肌（m.缝匠肌）浸入含有2.5-10 × 10- 4 w/v游离碱咖啡因的林格氏溶液中，张力产生，肌肉收缩。根据剂量对挛缩进行分级，并在移除药物后迅速逆转。高浓度的咖啡因会产生不可逆的挛缩。2在浸泡在等渗K2 SO 4或KCl溶液中的肌肉中，咖啡因会产生与保存在林格氏液中的肌肉完全相同的肌肉挛缩。将肌肉在等渗K2 SO 4溶液中长时间浸泡（96小时）不会降低其对咖啡因的反应性。3当移液管尖端位于细胞膜外表面时，将咖啡因从微量移液管局部应用于肌纤维会产生局部挛缩。当尖端插入纤维时，未观察到挛缩，表明咖啡因的作用仅限于肌膜。4 In浓度低于10 - 3 w/v的咖啡因不会改变肌纤维的静息Meinhrane电位。药物也没有显着降低横肌纤维的阻力。5这表明，咖啡因在肌纤维膜启动一个过程，激活纤维内部的收缩机制。这一过程被认为与通过传播的动作电位激活的过程相同。连接膜和收缩元件的过程（或多个过程）的性质尚不清楚，但目前的结果表明，这不太可能是电流或电位的变化。
1When a frog's striated muscle (m. sartorius) is immersed in Ringer solution containing 2.5–10 × 10–4w/v of the free base caffeine tension develops and the muscle contracts. The contracture is graded according to dose and reverses rapidly upon removal of the drug. Higher concentrations of caffeine produce an irreversible contracture.2In a muscle immersed in isotonic K2SO4or KCl solution caffeine produces exactly the same kind of muscle contracture as in a muscle kept in Ringer's fluid. Prolonged soaking (96 hours) of a muscle in isotonic K2SO4solution does not reduce its responsiveness to caffeine.3Local application of caffeine from a micropipette to a muscle fibre produces a localized contracture when the tip of the pipette is at the outer surface of the cell membrane. When the tip is inserted into the fibre no contracture is observed indicating that the caffeine action is confined to the muscle membrane.4In concentrations helow 10‐3w/v caffeine does not alter the resting meinhrane potential of iituscle fibres. Neither does the drug markedly reduce the transverse niuscle iiienibraiie resistance.5It is suggested that caffeine at the niuscle membrane starts a process which activates the contractile mechanism in the interior of the fibre. This process is believed to be the same as that activated by the propagated action potential. The nature of the process (or processes) linking the membrane to the contractile elements is unknown hut the present results makes it unlikely that it is an electric current or potential change.