Effects of A20 mRNA Expression Induced by Thyroxin on Pancreatic Islets β Cells

Objective To probe the effect of A20 mRNA expression induced by Thyroxin on pancreatic islets β cells,and to observe the morphological change at the same time.Methods Serum Insulin was assayed using radioimmunoassay(RA) methods and fasting serum glucose(FSG) concentrations were determined by the glucose oxidase technique.The determination of DNA fragmentation extracted from β cells was analyzed by agarose gel electrophoresis.The total RNA extracted from them was used to RT-PCR to determine the expression of A20 mRNA.Results The serum level of insulin of the rats in the groups that T4-treated for 14d and 21d were significantly decreased when compared with the controlled group(P0.05),while the serum level of FG of rats in both of the groups was significantly increased when compared with the controlled group(P0.01).Typical apoptosis ladder was observed in agarose gel electrophoresis of the DNA in the groups that T4treated for 14d and 21d,but not in others.The level of A20 mRNA expression was significantly decreased in T4-treated group administered for 14d compared with that of 7d(P0.01),but not found in other groups.Conclusion The mechanism of the apoptosis in pancreatic islets β cells induced by T4 maybe in connection with the incontinuous expression of anti-apoptosis protein A20 in it.