| Objective: To assess the expression of thioredoxin (TRX) and thioredoxin-interacting protein (TXNIP) expression in pancreas of diabetic rats and the effects of telmisartan on it.Methods: Thirty male SD rats were randomly assigned to a normal control (N) group, a diabetic (D) group, and a telmisartan treated diabetic (T) group. We used experimental animal model of type 2 diabetes mellitus (T2DM) that was induced by a combine of 4 weeks diet rich in fat and sugar and a single intraperitoneal injection of streptozotozin (STZ) (30mg/kg). Rats in T group were treated with telmisartan 10mg/ (kg·d) by gastric perfusion for 8 weeks. Plasma superoxide dismutase (SOD), malonaldehyde (MDA) and catalase (CAT) levels were measured to evaluate the degree of oxidative stress in rats. Fasting plasma glucose and insulin levels were also measured. The expression levels of insulin, TRX and TXNIP in islets were analysed by immunohistochemical. The TRX and TXNIP expression in pancreas were also analysed by RT-PCR and western blot. Results: The levels of mean fasting plasma glucose, MDA and TXNIP expression in pancreas were higher in D and T groups than in N group (P<0.05), the differences of levels of fasting plasma glucose between D group and T group were not statistically significant, but the levels of mean fasting plasma MDA and TXNIP expression in pancreas were lower in T group than in D group (P<0.05). The levels of mean fasting plasma insulin, SOD, CAT and expression of insulin and TRX in pancreas were lower in D and T groups than in N group (P<0.05), but were higher in T group than in D group (P<0.05).Conclusions: The expression of TRX was lower in pancreas of T2DM rats than in normal control rats, but expression of TXNIP was higher. Treatment with telmisartan might down-regulate the expression of TXNIP, up-regulate the expression of TRX, and improve the oxidative stress and hypoinsulinemia in T2DM rats, which indicated that islet function was ameliorated.
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