The Experimental Studys Of Effects Of Nicorandil On Myocardial Ischemia/Reperfusion- Induced Arrhythmias In Rats

Objective:To investigate the effects of Nicorandil on myocardial ischemical/reperfusion-induced arrhythmias and infarct size in rats.Methods:Eight-four Wister rats were randomly divided into six groups:N1( N:Nicorandil) group,N2 group,N3 group,Lidocaine group,Saline group and Sham operating group (control group). Myocardial ischemia reperfusion injury model was produced by ligaturing anterior descending branch of left coronary artery for 30 minutes and reperfusing for 360 minutes in rats. Apart from Sham operating group, others were administered with different drugs: N1,N2,N3 group—Nicorandil,Lidocaine group- Lidocaine,Saline group- Saline。Electrodes were attached to each limb for recording the surface electrocardiogram(ECG) and lead II ECG was monitored continuously throughout the experiment. After experiment, LDH and CK-Mb levels in blood were measured and the Infarct size was measured by using the staining agent NBT.The incidence rate of arrhythmia was estimated by using the method of Lepran, L[19]. Eight-four Wister rats were studied and the final experimental data were obtained from 64 rats, consisting of six groups: N1 group(n=11),N2 group(n=9),N3 group(n=10),Lidocaine group(n=12),Saline group(n=9) and Sham operating group(n=13).Results: 1.The mortality significantly decreased in N2 group, N3 group ,Lidocaine group ,Sham operating group as compared with Saline group(P<0.05)。2.The average arrhythmia scores significantly decreased in N2 group, N3 group ,Lidocaine group as compared with Saline group(P<0.01)。3. The Infarct size significantly decreased in N1 group ,N2 group, N3 group as compared with Saline group(P<0.05),but no difference between N1 group ,N2 group and N3 group. 4.The LDH and CK-Mb levels in blood significantly decreased in N1 group ,N2 group, N3 group as compared with Saline group(P<0.05).