肝细胞质膜Na^+-K^+-ATP酶细胞化学定位及其定量研究  

Ultrastructural Localization and Quantitation of Na + K + ATPase Activity on Plasmalemma of Hepatocytes

作　　者：沈秀成[1] 凌诒萍[1] 柳晓慧[1] 钟慈声[1] 

机构地区：[1]上海医科大学生物物理学教研室

出　　处：《电子显微学报》1997年第3期327-332,共6页Journal of Chinese Electron Microscopy Society

基　　金：上海市高教局科研基金

摘　　要：家兔肝细胞质膜Ｎａ＋－Ｋ＋－ＡＴＰ酶的定位研究，采用对硝基苯酚磷酸盐为底物，铈为捕捉剂，反应产物分布于肝细胞质膜窦状隙面、侧面和胆小管区。用电镜Ｘ射线显微分析法对胆小管区反应产物进行分析，从谱线上可见明显的ＰＫα峰和ＣｅＬ峰，证明反应产物为磷酸铈（Ｃｅ２（ＰＯ４）３）；切片在不含哇巴因、含哇巴因及除去底物的三种孵育液中进行反应后，分别对其胆小管区反应产物进行定量测定，铈量的峰背比为１．１８±０．３６，０．４８±０．２３和０（Ｐ＜０．０１）。结果说明Ｘ射线显微分析法是能用作Ｎａ＋－Ｋ＋－ＡＴＰ酶活性定量分析的一种较好手段。从实验中证明胆小管质膜上也有Ｎａ＋－Ｋ＋－ＡＴＰ酶分布，可参与维持细胞膜内外Ｎａ＋浓度梯度。Cytochemical localization of Na + K + ATPase in rabbit hepatocytes was studied by using p nitrophenyl phosphate as the substrate and using cerium as the capture agent.The reaction products were localized in the sinusoidal,lateral and bile canalicular membranes.X ray microanalysis was used for qualitative and quantitative analysis of the reaction products located on the canalicular membrane.Prominent P Kα and Ce L peaks appeared in the X ray spectrum.It suggests that the reaction products are cerium phosphate.The reaction products on the canalicular membrane in sections,which were incubated respectively in the standard medium without ouabain,with ouabain and substrate free,were measured quantitatively.It showed that the peak and background ratios (P/B) of cerium X ray counts were 1 18±0 36,0 48±0 23 and 0 respectively(P<0 01).These results demonstrate that the X ray microanalysis is a good tool for quantitative study of Na + K + ATPase activity.This work offers an evidence that the Na + K + ATPase located on the canalicular membrane can participate in maintaining the Na + concentration gradient,which provides energy for uptaking the bile acid through the Na + cotransport system.

关 键 词：肝细胞质膜 质膜 钠 钾 ATP酶 定位 细胞化学 

分 类 号：Q－336[生物学] Q26