摘要
目的 探讨严重烫伤大鼠肝细胞中胰岛素信号转导缺陷的环节 ,初步阐明严重烫伤后机体产生胰岛素抵抗的分子基础。 方法 以 30 %体表面积Ⅲ度烫伤大鼠为模型 ,采用麦胚凝集素 葡聚糖 4B亲和层析技术 ,部分纯化大鼠肝细胞胰岛素受体 ,通过胰岛素受体结合、受体蛋白自身磷酸化、SDS 聚丙烯酰胺凝胶电泳放射自显影和外源性底物磷酸化方法 ,观察烫伤大鼠早期肝细胞胰岛素受体结合行为、受体β 亚基自身磷酸化和受体酪氨酸蛋白激酶 (TPK)活性的变化。 结果 大鼠烫伤后 3d ,肝细胞胰岛素受体最大结合容量及亲和力无明显改变 ;受体 β 亚基自身磷酸化能力明显下降 ;受体TPK活性明显降低 ,对胰岛素刺激的反应性明显减退。 结论 严重烫伤后 ,大鼠肝细胞中的胰岛素信号转导发生偶联障碍 ,导致胰岛素生物效应受体后缺陷 ,可能是胰岛素抵抗发生的分子基础。
Objective To investigate the mechanism of hepatocytic insulin signal transduction defects in severely scalded rats, so as to clarify the molecular basis of postburn insulin resistance. Methods Wistar rats inflicted by 30% Ⅲ degree scalding on the back were employed as the model. The rat hepatocytic insulin receptor was partially purified by wheat germ agglutinin (WGA) sepharose 4B affinity chromatography. The change of receptor tyrosine protein kinase (TPK) activity, the receptor β subunit autophosphorylation and the hepatocytic insulin receptor binding behavior of scalded rats during early stage of scalding were observed by means of insulin receptor binding test, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) autoradiography of phosphorylation of insulin receptor and phosphorylation of exogenous substrate. Results There exhibited no evident changes of hepatocytic insulin receptor maximal binding capacity and affinity at 3 postburn days (PBDs) in scalded rats. The autophosphorylation capacity of the receptor β subunit decreased significantly. And the receptor TPK activity decreased obviously and its reaction to insulin stimulation decreased markedly. Conclusion The defects of the insulin receptor signal transduction in hepatocyte leading to the post receptor defects of insulin biological effects might be molecular mechanism of postburn insulin resistance. [
出处
《中华烧伤杂志》
CAS
CSCD
2002年第4期220-222,共3页
Chinese Journal of Burns
