Study on protection of a Shenfu injection against myocardial ischemia-reperfusion arrhythmias in aged mice / 中华老年医学杂志

ABSTRACT

Objective@#To investigate the protective effects of pretreatment with a Shenfu(SF)injection on arrhythmias induced by myocardial ischemia-reperfusion(IR)injury in aged mice.@*Methods@#Thirty 18-month-old C57BL/6J mice were randomly divided into 3 groups(n=10, each group) the sham treatment group(receiving sham operation without thoracotomy), the IR group(undergoing the ligation of the left anterior descending coronary artery with ischemia for 30 min and reperfusion for 2 h)and the SF group(receiving SF intraperitoneal injection of 10 ml/kg 30 min before thoracotomy and the same treatment as the IR group). Arrhythmias were monitored, and serum levels of creatine kinase-isoenzyme(CK-MB), troponin(cTnI)and tumor necrosis factor α(TNFα), and the ratio of myocardial connexin 43(Cx43)phosphorylation(ser368)to total protein(p-Cx43/t-Cx43)were detected in the three groups.@*Results@#Ventricular arrhythmias occurred in the IR and SF groups.Compared with the IR group, ventricular arrhythmias in the SF group were alleviated, the frequency of ventricular premature systolic episodes was reduced(36.6±13.5 times vs. 48.4±22.1 times), the frequency of ventricular tachycardia/fibrillation decreased(3.4±1.8 times vs. 7.6±3.5 times), and the total duration of ventricular tachycardia/fibrillation episodes was shortened(8.9±4.5 times vs. 17.7±5.1 times)in the SF group(P<0.05), but there was no significant difference in arrhythmia scores(1.8±1.2 points vs. 1.9±1.7 points, P>0.05)between the two groups.Compared with the sham treatment group, serum levels of CK-MB, cTnI and myocardial TNF(increased in the IR and SF groups(P<0.05), and their levels were lower in the SF group than in the IR group(P<0.05). Compared with the sham treatment group, the ratio of Cx43 ser368/total protein was lower in the IR and SF groups, but was higher in the SF group than in the IR group(P<0.05).@*Conclusions@#SF pretreatment can significantly reduce IR-induced arrhythmias in aged mice possibly by reducing TNF(and up-regulating the phosphorylation activity of Cx43.