【摘要】 目的 观察亚砷酸钠(NaAsO2)对胰岛β细胞NIT-1胰岛素(Ins)合成与分泌的影响。 方法 体外培养NIT-1细胞，NaAsO2处理后，以MTT法检测细胞的增殖活性，用ELISA法测定Ins分泌情况，RT-PCR法检测Ins mRNA的表达。 结果 (1)当NaAsO2浓度大于4μmol/L时抑制细胞增殖，细胞增殖抑制率随NaAsO2浓度的增加及作用时间的延长而增加。(2)作用24h，8μmol/L组不同浓度葡萄糖刺激的Ins分泌和Ins mRNA表达均明显减少(P<0.05);作用48h，4μmol/L组和8μmol/L组不同浓度葡萄糖刺激的Ins分泌和Ins mRNA表达均明显减少(P<0.05)，而且8μmol/L组对高糖(16.5 mmol/L)刺激的Ins分泌与基础(5.5mmol/L)Ins分泌无明显差异。 结论 砷对NIT-1细胞Ins分泌和Ins基因表达的影响同作用时间和剂量有关，Ins合成与分泌障碍可能是砷影响胰岛β细胞功能进而引发DM的机制之一。

　　【关键词】 砷;NIT-1细胞;胰岛素分泌;胰岛素基因;糖尿病

　　Effect of NaAsO2 on insulin synthesis and secretion of NIT-1 insulinoma cells. WANG Rui, ZHANG Bing-yin, LI Li, et al. Department of Histology and Embryology, College of Medicine, Shihezi University / Key Laboratory of Xinjiang Endemic and Ethnic Diseases,Xinjiang Production and Construction Corps, Shihezi 832002, China

　　Corresponding author: MU Xiao-ling, E-mail: xiaolingmr@163.com

　　【Abstract】 Objective To investigate the effect of NaAsO2 on insulin synthesis and secretion of NIT-1 insulinoma cells (pancreatic islet β-cells). Methods The NIT-1 cells were cultured in vitro, after treatment with NaAsO2, their proliferation activity was determined by MTT, glucose stimulated insulin secretion (GSIS) was measured by ELISA, and level of insulin mRNA expression was detected by RT-PCR. Results (1). The proliferation of NIT-1 insulinoma cells was inhibited in a time-and-dose dependant manner when the concentration of NaAsO2 was higher than 4μmol/L. (2). In exposing to NaAsO2 for 24h, the GSIS and Ins mRNA expression of NIT-1 insulinoma cells of the 8μmol/L group were both significantly decreased (P<0.05). In exposing to NaAsO2 for 48h, the GSIS and Ins mRNA expression of NIT-1 insulinoma cells of the 4μmol/L and 8μmol/L groups were both significantly decreased (P<0.05). And the GSIS of the 8μmol/L group was not significantly different in response to 16.5mmol/L glucose from the basal insulin secretion (5.5mmol/L). Conclusion With a time-and-dose dependence, arsenic can exert inhibitory effect on insulin secretion and insulin mRNA expression of NIT-1 insulinoma cells. The disturbance of insulin synthesis and secretion may be the contribution of arsenic impaired β-cell functions to the development of DM.

　　【Key words】Arsenic; NIT-1 insulinoma cells; Insulin secretion; Insulin gene;Diabetes mellitus