肥大心肌细胞膜阴离子位点的变化

Changes of anionic sites on hypertrophic myocardial cell membrane

目的 :旨在研究肥大心肌细胞膜损伤的分子病理学基础。方法 :本实验采用大鼠腹主动脉缩窄模型 ,以聚乙烯亚胺 (PEI)为阳离子探针 ,观察肥大心肌细胞膜基板阴离子位点的变化 ,并测定心肌细胞内的Ca2 + 含量和细胞膜的Ca2 + ATP酶活性。结果 :对照组大鼠心肌细胞表面PEI颗粒沿基膜以 4 0～ 80nm间距呈较规则的点阵式、线性排列。手术组心肌细胞表面PEI颗粒明显减少 ,并可见心肌细胞基膜与质膜分离 ,基膜断裂 ;心肌细胞内的Ca2 + 含量增加 ,细胞膜的Ca2 + ATP酶活性降低。结论 :表明肥大心肌细胞膜基板阴离子位点减少 。

Objective:To investigate the lesion of hypertrophic myocardial cell membrane in the molecular level.Method:The model of rat abdominal aortic constraction was adopted,the distribution of anionic sites at the basal lamina of hypertrophic myocardial cells in the rats was observed with a cationic probe,polyethylenimine(PEI),Ca\+\{2+\} level in myocardial cell and activity of Ca\+\{2+\}\|ATPase of myocardial sarcolemma were measured Result:It was observed that the anionic sites of basal lamina of the myocardial cells in control rats were orderly arranged in linear manner at the distarce of 40～80 nm.The number of PEI particles were reduced significantly in operated rats,there was a dissociation between basal lamina and plasma membrane,the loss of lamina integrity and the rupture of the plasma membrane in operated rats was observed. Ca\+\{2+\} level in myocardial cell and activity of Ca\+\{2+\}\|ATPase of myocardial sarcolemma were markedly decreased.Conclusion:These results indicate that there is a decrement of the anionic sites of basal lamina and there is a membrane protective barrier dysfunction in hypertrophic myocardial cells.