小檗碱对NIT-1细胞胰岛素分泌和葡萄糖激酶活性的影响

本文探讨小檗碱对NIT-1细胞胰岛素分泌的影响及其分子机制。采用不同浓度小檗碱干预NIT-1细胞后，以放射免疫法、液体闪烁计数法、酶法分析及Western blotting分别检测其胰岛素水平、葡萄糖利用、葡萄糖激酶(GK)活性、GK和葡萄糖激酶调节蛋白(GKRP)的表达。结果表明，在高浓度葡萄糖刺激下，与空白对照组相比，小檗碱组的NIT-1细胞胰岛素分泌增加、葡萄糖利用活跃，且GK酶活性增强、GK表达增加，而GKRP表达降低(P<0.05)。结果表明，小檗碱促进NIT-1细胞高浓度葡萄糖诱导的胰岛素分泌，可能与其作为GK激活剂，使NIT-1细胞葡萄糖利用增加、GK酶活性及表达增强有关。

Effect of berberine on insulin secretion and glucokinase activity of NIT-1 cells

To investigate the effect of berberine on insulin secretion of NIT-1 cells stimulated by glucose and the possible molecular mechanism,we used radioimmunoassay,scintillation counting technique,enzymatic method and Western blotting to measure the effects of berberine on insulin secretion,glucose utilization,the activity of glucokinase(GK) and protein level of GK and GK regulation protein(GKRP).Compared with untreated group,insulin secretion level,glucose utilization,the activity and protein level of GK in NIT-1 cells stimulated by high concentration of glucose were increased significantly in berberine group(P<0.05),while the protein level of GKRP in berberine group decreased markedly.In conclusion,berberine can promote insulin secretion of NIT-1 cells induced by high concentration of glucose.The possible molecular mechanism may be associated with berberine acting as a GK activator,improving glucose utilization,enhancing the activity and protein expression level of GK,as well as decreased the protein level of GKRP.