LONG-TERM TREATMENT WITH GLIBENCLAMIDEINCREASES SUSCEPTIBILITY OF STREPTOZOTOCIN-INDUCED DIABETIC RAT HEART TO REPERFUSION-INDUCED VENTRICULAR TACHYCARDIA

摘要

This study was aimed to investigate the effects of treatment with glibenclamide (GLIB) on the susceptibility of streptozotocin (STZ)-induced diabetic heart to ischemia/reperfusion insults. Since 4 weeks after the injection of STZ, rats had been treated with GLIB (STZ-GLIB group) or vehicle (STZ-VEH group) for 8 weeks. We studied the recovery of cardiac performance, released creatine kinase (CK) and incidence of ventricular arrhythmias during the reperfusion period. Each heart was subjected to 5 min of global low flow ischemia followed by 25 min of no flow ischemia, with subsequent 30 min of reperfusion. The recovery of cardiac performance and the released CK during reperfusion period was significantly lower in both STZ-VEH and STZ-GLIB groups than in age-matched control (CNT) group. Reperfusion resulted in an incidence of ventricular fibrillation in 23 and 21 % in STZ-VEH and STZ-GLIB groups, respectively. These values were significantly lower than that of CNT group. More importantly, the incidence of ventricular tachycardia in STZ-GLIB group was significantly higher than that in STZ-VEH group and was not significantly different from that in CNT group. Our results suggest that STZ-induced protection against reperfusion-induced ventricular arrhythmias in diabetic heart may be partially abrogated by long-term treatment with GLIB.