Protective effect of trimetazidine for the rat myocardial tissue after exhaustion exercise / 解放军医学杂志

ABSTRACT

Objective To explore the protective effect of trimetazidine on the myocardial tissue of rats by observing the oxidative stress, apoptosis and energy metabolism in myocardial tissue of rats after exhausted exercise. Methods Thirty healthy adult male Wistar rats were randomly assigned to three groups (10 each) quiet control group (C), exhausted exercise group (E) and exhausted exercise plus trimetazidine group (TE). Exhausted exercise model was established by forcing the rats swim ceaselessly, rats in group TE received hydrochloric acid trimetazidine (10mg/kg) for intervention. The myocardial tissue of rats was collected after the last exhausted exercise. The myocardial tissue of rats was evaluated by HE staining. The concentrations of superoxide dismutase (SOD), glutathione peroxidase 1 (GSH-Px) and malondialdehyde (MDA) in rats' myocardial cell mitochondria were detected by spectrophotometry. RT-PCR and immunohistochemistry were performed to quantify the mRNA and protein levels of Bax, Bcl-2 and uncoupling protein 2 (UCP2) in myocardial tissue of rats. Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) assay was employed to detect the apoptotic rate of myocardial tissue. Results Compared with group C, the SOD and GSH-Px activities in groups E and TE were reduced (P<0.01), while the MDA activity was increased (P<0.01), and more obvious changes were in group E. The SOD and GSH-Px activities decreased, while the MDA activity increased in group E than in group TE (P<0.01). Compared with group C, the apoptotic rate of myocardial tissue increased in groups E and TE (P<0.01), and the highest apoptotic rate was in group E (P<0.01). Furthermore, the mRNA and protein levels of Bax were significantly elevated in groups E and TE (P<0.01), and the highest expression was in group E (P<0.01). The mRNA and protein levels of BCL-2 were significantly reduced in groups E and TE (P<0.01), and the lowest expression was in group E (P<0.01). Meanwhile, compared with group C, the mRNA and protein expression of UCP2 was significantly increased in groups E and TE (P<0.01). After treatment with hydrochloric acid trimetazidine, the UCP2 expression in group TE was relative decreased than in group E (P<0.01). Conclusion Trimetazidine can reduce the oxidative stress and apoptotic rate of myocardial tissue of rats after exhausted exercise, indicating it plays an important protective role for the myocardial tissue of rats.