心肌细胞钙的电子显微镜放射自显影和冷冻复型放射自显影实验

An experiment on calcium of myocardium cells with freeze replica and autoradiography

[目的 ]从形态学角度进一步研究钙离子在心肌细胞中的转运机制和分布规律 .[方法 ]以放射性钙离子为放射源 ,利用电子显微镜放射自显影和冷冻蚀刻 电子显微镜放射自显影方法对小鼠心肌细胞进行研究 .[结果 ]电子显微镜放射自显影实验结果显示 ,正常组的线粒体嵴完好 ,缺血对照组的线粒体肿胀 ,嵴不完整 ;腺苷三磷酸氯化酶组的线粒体较缺血对照组破坏较轻 ,嵴较完整 ;同位素标记的正常、缺血对照组、腺苷三磷酸氯化酶组中可观察到菊花状的银丝团散布于组织切片上 ,且主要分布于内质网和线粒体上 ,缺血对照组的线粒体上有较多的银丝团 .冷冻复型 电子显微镜放射自显影结果显示 ,缺血对照组细胞核膜的E片劈裂面和P片劈裂面上核孔稀少 ,分布不均匀 ;腺苷三磷酸氯化酶组质膜蛋白颗粒丰富 ,且分布均匀 ;在各组复型膜上可见到菊花状银丝团 .缺血缺氧时细胞质膜蛋白颗粒减少 ,提示做为钙通道的糖蛋白受体减少 ,而此时线粒体钙却增加 .[结论 ]钙离子的进入更多地依赖于钠、钙交换 ,而不是钙通道 .高能磷酸盐制剂改善了细胞膜的功能 ,防止了钙离子在线粒体内的聚集 .

OBJECTIVE To further study the transport mechanism and distributive regulation of Ca 2+ in myocardium cells on the basis of morphology.METHODS To use 45 Ca 2+ as radioisotope and to take advantage of electron microscopic autoradiography combined with freeze replica to study the myocardium cells in mice.RESULTS The cristae of mitochondrias in normal group are complete;the mitochondrias in ischemia control group are swelling and the cristae are incomplete;the mitochondrias of adenosine triphosphate magnesium chloride (ATP MgCl 2) group are damaged slightly, however the cristae are relatively complete compared with ischemia control group.On the sections labelled with radioisotope in normal group, ischemia control group and ATP MgCl 2 group,the chrysanthemum like silver grains which mainly are distributed in endoplasmic reticulum and mitochondrias can be observed ; and more silver grains found on the mitochondrias of ischemia control group.Few nuclear pores are distributed unevenly on the E surface and P surface of nuclear membrane,whereas abundant plasma membrane protien granules are well distributed in ATP MgCl 2 group.The chrysanthemum like silver grains can be found on the freeze replica of each group.During ischemia hypoxia,the membrane protein granules are decreased, indicating that glucoprotein receptors acting as Ca 2+ path are decreased,but the Ca 2+ in mitochondrias are increased, CONCLUSION The entry of Ca 2+ into cells is even more dependent on Na +/Ca 2+ exchange instead of Ca 2+ path.High energy phosphate improves the function of plasma membrane,prevented Ca 2+ from accumulating in mitochondrias.