The effect of phenothiazines upon maintenance of membrane integrity in the cultured myocardial cell.
The effect of phenothiazines upon maintenance of membrane integrity in the cultured myocardial cell.
复制标题
吩噻嗪对维持培养的心肌细胞膜完整性的影响。
DOI：
10.1016/s0022-2828(86)80428-x
复制
发表时间：
1986
影响因子：
5
通讯作者：
Homcy,CJ
中科院分区：
文献类型：
--
作者：
Scott,JA;Khaw,BA;Fallon,JT;Locke,E;Rabito,CA;Peto,CA;Homcy,CJ
培养的心肌细胞为检测维持细胞活性和肌膜完整性的因素提供了明确的模型。我们的数据表明，心肌细胞膜完整性的自发丧失是一个钙依赖的过程，从而为研究钙发挥这一作用的机制提供了方法。抗肌球蛋白抗体染色和碘化丙啶摄取定量测定细胞膜的完整性。细胞膜的完整性与培养液中的钙浓度呈负相关。这种膜完整性的丧失是钙调蛋白依赖性的，如下所示：(1)吩噻嗪(三氟拉嗪；氯丙嗪；异丙嗪)和结构不同的钙调蛋白抑制剂在与已知抑制钙调蛋白的浓度相似的浓度下阻止肌膜缺陷的形成；(2)吩噻嗪和钙对膜完整性的影响表现出竞争性的相互作用。电子显微镜证实，暴露于高浓度吩噻嗪的细胞的肌膜是完整的，尽管这些细胞发生了代谢变化，表现为对低分子量探针碘化丙啶的膜通透性增加，线粒体精细结构的退化变化，细胞质中自噬空泡的积累和收缩能力的丧失。这些发现表明，钙调蛋白抑制化合物能够保护心肌细胞膜的完整性，干扰钙依赖的过程，这与培养中这些细胞的自发磨损有关。即使在肌膜没有明显缺陷的情况下，这些药物在高剂量时也会出现显著的细胞内变化。
The cultured myocardial cell provides a defined model for examining factors which are responsible for maintaining cellular viability and sarcolemmal integrity. Our data indicates that the spontaneous loss of myocyte membrane integrity is a calcium-dependent process and thus provides a method for examining the mechanism through which calcium exerts this effect. Antimyosin antibody staining and propidium iodide uptake were used to quantitate membrane integrity. The integrity of the cell membrane was inversely related to the calcium concentration in the culture medium. This loss of membrane integrity was calmodulin-dependent as demonstrated by the following: (1) phenothiazines (trifluoperazine >chlorpromazine>promethazine) and structurally dissimilar calmodium-inhibitors prevented the formation of sarcolemmal defects at concentrations similar to those known to inhibit calmodulin; (2) phenothiazines and calcium demonstrated a competitive interaction with respect to this effect on membrane integrity. Electron microscopy confirmed the integrity of the sarcolemma of the cells exposed to high phenothiazine concentrations although metabolic alterations occurred in these cells as evidenced by an increased membrane permeability to the low molecular weight probe propidium iodide, degenerative changes in the fine structure of the mitochondria, the accumulation of autophagic vacuoles in the cytoplasm and the loss of contractile ability. These findings indicate that calmodulin inhibitory compounds are capable of preserving the membrane integrity of cardiac myocytes, interfering with a calcium-dependent process that is associated with the spontaneous attrition of these cells in culture. Significant intracellular alterations appear at high doses of these agents even while the sarcolemma is free of gross defects.