烫伤早期大鼠肾皮质细胞氧自由基、Ca^（2＋）细胞化学和Ca^（2＋）－Mg^（2＋）－ATP酶活性的变化

Study of Ca^(2+)-Mg^(2+)-ATPase activities,Ca^(2+) and H_2O_2 cytochemistry of rat renal cortex cell during early burn

研究重度烫伤大鼠肾皮质细胞膜（质膜、内质网及线粒体膜）Ｃａ２＋－Ｍｇ２＋－ＡＴＰ酶活性、细胞内Ｃａ２＋定位和半定量及肾皮质内Ｈ２Ｏ２（氧自由基）定位，以探讨烫伤早期肾损伤的机制。方法：化学法和细胞化学法。结果：发现肾小管细胞内Ｃａ２＋浓度升高在烫伤后６０ｍｉｎ达到高峰，Ｃａ２＋－Ｍｇ２＋－ＡＴＰ酶活性在６０或１２０ｍｉｎ为最低，并与亚细胞结构的损伤程度显著相关。烫伤后３０ｍｉｎ肾皮质间质毛细血管及肾小球毛细血管壁出现Ｈ２Ｏ２细胞化学阳性沉积物，６０ｍｉｎ时消失。以上变化在观察时间内（５ｈ）具有可恢复性。结论：严重烫伤时肾缺血，皮质毛细血管内皮细胞受氧自由基损伤，改变了血管通透性，引起组织水肿，继而Ｃａ２＋泵活性下降，Ｃａ２＋过载，进一步影响细胞结构和功能。

Objective:In order to investigate the mechanism of renal injury during early brun,the activities of Ca2+-Mg2+-ATPase,Ca2+ cytochemistry and EDX semi-quantitive determination of renal cortex cell membranes were studied in rats.Methods:The chemistry and cytochemistry techniques were used.Results:There were climax of calcium deposition at 60 min,the lowest activities of Ca2+-Mg2+-ATPase at 60or 120 min postburn and significant correlation between the decrease of Ca2+-Mg2+-ATPase activities and the severe injury of cellular structure of the kidney.The positive deposition of H2O2 showed on the capillary wall of renal interstice and glomerulus at 30 min and disappeared at 60 min.The above mentioned changes were partially reversible during experiment.Conclusion:Severe burns could induce renal ischemia,resulting in production of oxygen radical,increase of vascular permeability,decrease of Ca2+-Mg2+-ATPase activity,and calcium overload.Renal cellular structure and function are further effected.