Protective effects of N-acetylcysteine in isoproterenol-induced myocardium injury in rats.

Isoproterenol (ISO) has been found to cause severe injury in the myocardium. The aim of this study was to investigate the protective effects of N-acetylcysteine (NAC) on ISO-induced myocardial injury in rats and its underlying mechanisms. Fouty male Wistar rats were randomly divided into four groups: control, ISO, NAC, and ISO + NAC group. Myocardial histopathological observation were performed; The activities of creatine kinase isoenzyme-MB (CK-MB) and lactate dehydrogenase (LDH) were examined; Myocardium TNF-alphaand IL-1beta gene expressions were examined by RT-PCR analysis; Myocardial expressions of TNF-alphaand IL-1betaproteins were observed by immunohistochemical assay and western blotting analysis. The myocardial injury induced by ISO was significantly reduced by the treatment of NAC as judged by the reduction of myocardial necrosis. Compared with ISO group, rats pre-injected with NAC showed a significant decrease in the activities of cardiac marker enzymes such as CK-MB and LDH in serum. NAC inhibits the pro-inflammatory factors expressions (TNF-alphaand IL-1beta) stimulated by ISO. In conclusion, NAC exerts significant cardio-protective effects against ISO-induced myocardial injury in rats, likely regulating pro-inflammatory factors expressions.