Possible Protective Effect of Nicorandil on Experimentally Induced Myocardial Infarction in Diabetic Albino Rats Treated with Glimepiride or Rosiglitazone

type 2 diabetes mellitus affects a large population worldwide. The major cause of mortality in type 2 diabetic patients is the cardiovascular complications.The aim of the present work is to study the effect of nicorandil on isoprenaline (ISO)-induced infarction in diabetic albino rats treated with glimepiride or rosiglitazone.Methods: Type 2 diabetes was induced in rats by I.P. injection of nicotinamide (100mg/kg) followed by streptozotocin (60mg/kg). One week later, the rats received the drugs [nicorandil (6mg/kg/d), glimepiride (4mg/kg/d) or rosiglitazone (3mg/kg/d)] for another one week. At the last day of the experiment, MI was induced in diabetic rats by S.C. ISO (300mg/kg). The parameters studied were, ECG changes (heart rate and T-wave voltage), infarct size, and creatine kinase-MB serum level.Results: Oral administration of nicorandil for one week has cardioprotective effect against ISO-induced MI in diabetic rats, evidenced by significant decrease in T-wave voltage, infarct size, and CK-MB serum level. Oral administration of glimepiride for one week has insignificant effect on ISO-induced MI in the previously mentioned parameters. When glimepiride is combined with nicorandil, it was found that glimepiride has insignificant effect on cardioprotective effect of nicorandil. Oral administration of rosiglitazone for one week has insignificant effect on ISO-induced MI in the previously mentioned parameters. When rosiglitazone is combined with nicorandil, it was found that rosiglitazone abolish the effect produced by nicorandil.