Influence of tanshinone on rabbit malignant arrhythmias and calmodulin signal transduction pathway after myocardial infarction / 心血管康复医学杂志

ABSTRACT

Objective: To explore influence of tanshinone on rabbit malignant arrhythmias and calmodulin signal transduction pathway after myocardial infarction. Methods: A total of 30 rabbits were randomly and equally divided into sham operation group (sham group), model group and tanshinone group. Acute myocardial infarction model was established through ligating left anterior descending branch of coronary. After modeling, the rabbits were randomly and equally divided into model group and tanshinone group. Incidence rate of malignant arrhythmias, action potential duration (APD) of three myocardial layers (namely endocardium layer, myocardium layer and epicardium layer), transmural dispersion of repolarization, Ca2+ concentration, compared among three groups. Results: Incidence rate of malignant arrhythmias in tanshinone group was significantly lower than that of model group (20.0% vs. 70.0%, P<0.01); compared with sham group, there were significant rise in transmural dispersion of repolarization, 90% APD, Ca2+ concentration, expression levels of calmodulin and calmodulin kinase Ⅱ of three layers in model group and tanshinone group (P<0.01 all) ; compared with model group, there were significant reductions in transmural dispersion of repolarization[(46.2±10.9) ms vs.(35.5±8.8) ms], 90% APD [epicardium layer, (231.5±17.4) ms vs.(211.0±16.3) ms], Ca2+ concentration [epicardium layer, (132.0±12.3) mmol/L vs.(102.3±10.3) mmol/L], expression levels of calmodulin [epicardium layer, (0.724±0.014) vs. (0.563±0.014)] and calmodulin kinase Ⅱ[epicardium layer, (0.759±0.019) vs. (0.589±0.017)] in tanshinone group, (P<0.05～0.01). Conclusion: Tanshinone possesses anti-malignant arrhythmias effect after myocardial infarction. Its mechanism may be regulating calmodulin and calmodulin kinase Ⅱ signal transduction pathway.