Objectives To study the effect of berberine on arrhythmia caused by stretch of isolated myocardial infracted (MI) hearts in rats.
Methods The study was carried out in the laboratory of Heilongjiang traditional Chinese medicine university. 40 Wistars were randomly divided into 4 groups: normal control group, berberine group, MI group, MI+ berberine group. After perfused on Langendorff, the model of MI was made with ligation of left anterior descending branch for 30 min. Berberine was dissolved in Tyrode's solution at a concentration of 300 µmol l−1. The hearts were stretched for 5 s by 0.2 ml. The effect of stretching was observed for 30 s, including 90% monophasic action potential (MAPD90), premature ventricular beats (PVB) and ventricular tachycardia (VT). Quantitative data were compared with ANOVA. Qualitative data were compared with a χ2 test. Differences with a value of p<0.05 were considered statistically significant.
Results MAPD90 in normal control and MI group obviously lengthened after the hearts were stretched (p<0.01). And MAPD90 in MI group was even longer than that of normal control group (p<0.05). Berberine has no influence on MAPD90 of basic condition (p>0.05), while it could reduce the lengthened MAPD90 after stretched (p<0.05 or p<0.01). The incidence rate of PVB and VT in normal control and MI group increased after stretched. 300 µmol/l berberine could reduce the incidence rate of PVB, and obviously inhibit the occurrence of VT (p<0.01).
Conclusions Berberine could obviously inhibit the occurrence of stretch-induced arrhythmias after myocardial infarction.