Objective To study the effects of ethanol on glucose-stimulated insulin secretion (GSIS) and glucokinase mRNA expression of NIT-1 insulinoma cells.
Methods NIT-1 cells were exposed to various concentr ations of ethanol (0, 50, 100, 200, 400 mmol/L) for various periods of time (6, 12, 24 h).The metabolic activity was judged by methyl thiazolyl tetrazolium (MTT) assay.The level of insulin secretion was measured by radioimmunoassay.Additonally, relative level of gluco kinase mRNA expression was evaluated by RT-PCR method.
Results The metabolic activity was inhibited in dos-eand-time dependent manners.Afterexposed for 6 hours, ethanol increased the level of glucose-stimulated insulin secretion in the medium.After exposed for 12 and 24 hour, ethanol decreased the amount of glucose-stimulated insulin secretion in the medium.At 6 hour, ethanol upgraded gluco kinase mRNA expression.At 12 and 24 hours, ethanol upgraded glucokinase mRNA expression.
Conclusion Depending on the timing and concentrations, ethanol can exert both stimulatory and inhibitory effects on insulin secrection and glucokinase mRNA expression in NIT-1 cells.Influence of ethanol on glucokinase mRNA expression in NIT-1 cells maybe was one of the mechanisms involved in the effect of ethanol on insulin secretion.
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