Objective： To observe effects of different sulfonylurea compounds on expression of sulfonylurea receptor 2 （SUR2）in myocardium of the Goto-Kakizaki（GK）rats. Methods： Spontaneous diabetic GK rat models were divided into 6 groups： the diabetes model group, the Glibenclamide group, the Glipizide group, the Gliclazide group, the Glimepiride group and the positive control group（treated with insulin）, with 12 rats in each group. A normal control group was also set up for comparison. The expression of SUR2 in myocardium of the GK rats was investigated by radioligand binding assay. SUR2 mRNA expression in the myocardial cells of rats was detected through reverse transcriptase-polymerase chain reaction （RT PCR）. Results： Twelve weeks later, no significant difference was found in the SUR2 receptor density（Bmax）and affinity（Kd） between the sulfonylurea treated groups and the other 3 groups （P〉0.05）. There was no significant difference in SUR2 mRNA expression between the diabetic, insulin-treated diabetic and control groups （P〉0.05）. Cardiac SUR2 mRNA levels were not significantly different between sulfonylureas treated diabetic and non-treated diabetic rats （P〉0.05）. Conclusion： The diabetes itself does not affect the sulfonylurea receptor（SUR2） expression in myocardial tissues. Sulfonylureas at treatment dosage have no effect on receptor expression of SUR2.[著者文摘]