Mrak R E
Department of Pathology, University of Arkansas for Medical Sciences, Little Rock.
Neurotoxicology. 1990 Summer;11(2):367-73.
Ethanol is a well-recognized cause of muscle damage in humans. In vitro, ethanol decreases muscle fiber twitch tension by a mechanism unrelated to the electrical events of the motor endplates or muscle surface membranes. One possible explanation for this effect is a primary ethanol effect on calcium release from the sarcoplasmic reticulum (SR). Ethanol has been shown to progressively decrease a form of calcium release from isolated SR vesicles seen in vitro in the presence of high phosphate concentrations ("spontaneous calcium release"). In this study, ethanol is shown to have similar inhibiting effects on spontaneous calcium release from sarcoplasmic reticulum isolated from alcoholic rats and from pair-fed controls. This suggests that membrane adaptation to chronic ethanol exposure, such as has been described for brain and liver membranes, does not produce tolerance to ethanol effects on spontaneous calcium release in sarcoplasmic reticulum.
乙醇是人类肌肉损伤的一个公认原因。在体外，乙醇通过一种与运动终板或肌肉表面膜的电活动无关的机制降低肌肉纤维的抽搐张力。对此效应的一种可能解释是乙醇对肌浆网（SR）钙释放的直接作用。乙醇已被证明会逐渐减少在高磷酸盐浓度下体外观察到的从分离的SR囊泡释放的一种钙形式（“自发钙释放”）。在本研究中，乙醇对从酒精性大鼠和配对喂养对照大鼠分离的肌浆网的自发钙释放具有类似的抑制作用。这表明，如在脑和肝膜中所描述的那样，膜对慢性乙醇暴露的适应性不会产生对乙醇对肌浆网自发钙释放影响的耐受性。
