Effect of ethanol on insulin mRNA expression and function of pancreatic islet β-cells

  Objective   To examine primary cultured rat pancreatic islet cells and NIT-1 cells insulin secretion in response to a glucose challenge following exposure to different concentraions of ethanol, and to investigate the mechanism of the effect of ethanol on β-cell function.

  Methods   After NIT-1 cells and the primary cultured rat pancreatic islets cells were exposed to various concentraions of ethanol for certain time, the insulin secretion was measured by radioimmunoassay.Meanwhile, the levels of insulin mRNA expression were detected by R T-PCR method.

  Results   (1) Effect of ethanol on glucose stimulated insulin secretion(GSIS)and insulin mRNA expression in NIT-1 cells.At 6 h, ethanol increased GSIS.At 24 h and 12 h, ethanol decreased GSIS.At 6 h, ethanol(except for 400 mmol/L)upgraded insulin mRNA expression At 24 h, ethanol decreased insulin mRNA expression.(2)Effect of ethanol on GSIS and insulin mRNA expression in primary cultured rat pancreatic islet cells.Insulin release was increased at low concentration, but decreased markedly after exposed to high dosage of ethanol.Insulin mRNA expression was upgraded at low concentration, but began to decrease with the concentrations increasing.At 6 h, ethanol increased GSIS, but deccreased GSIS at 24 h.INS mRNA expression was upgraded at 6 h and began to decrease at 24 h.

  Conclusion   Depending on the timing and concentrations, ethanol can exert both stimulatory and inhibitory effects on insulin secretion and insulin mRNA expression in pancreatic islet β-cells.Influence of ethanol on insulin mRNA expression may be involved in the effect of ethanol on insulin secretion.