Protective effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats

Abstract

Objective To investigate the effect of verapamil administered at different time points on myocardial ischemia-reperfusion injury in rats, and explore the mechanism of myocardial protection.Methods The model of myocardial ischemia reperfusion in rats was established and 18 male SD rats were randomly divided into 3 groups,n =6 each. Verapamil dilution (0. 25 mg/kg) was pumped into verapamil1 group 10 min before ischemia, and verapamil dilution (0. 25 mg/kg) was pumped into verapamil-2 group 10 min before reperfusion. Normal saline (2 ml/kg) was pumped into IR group 10 min before ischemia.Rats were killed 60 min after reperfusion. The levels of serum cardiac Troponin T (cTnT) and the expression of myocardial Caspase-3 were evaluated. Histomorphological methods were used to analyze the extent of myocardial injury. Results The levels of serum cTnT and the expression of myocardial Caspase-3 in verapamil-1 group (4.60 ± 1.12) ng/L, (39.51 ±5.01)% were significantly lower than those in IR group (7. 70 ± 1.31 ) ng/L, (51.10 ±5. 30)% and verapamil-2 group (7. 23 ± 1.03) ng/L, (49. 35 ±4. 95 ) % ( P ＜ 0. 05 ). The levels of serum cTnT and the expression of myocardial Caspase-3 had no significant difference between verapamil-2 group and IR group (P ＞ 0. 05 ). The extent of myocardial injury in verapamil-1 group was significantly lower than that in IR group and verapamil-2 group (P ＜ 0. 05 ). The extent of myocardial injury had no significant difference between verapamil-2 group and IR group (P ＞0. 05). Conclusion Starting from 10 min before ischemia, verapamil has protective effects on myocardial ischemia/reperfusion injury. Starting from 10 min before reperfusion, verapamil does not provide protection on myocardial ischemia reperfusion injury. Key words: Verapamil; Myocardial ischemia; Reperfusion injury