Protective effect of L-carnitine on myocardial injury in rats with heatstroke

ABSTRACT

Purpose: To investigate the protective effect of L-carnitine on myocardial injury in rats with heatstroke. Methods: orty-eight rats were randomly divided into control, heatstroke and 25, 50 and 100 mg/kg L-carnitine groups. The last three groups were treated with 25, 50 and 100 mg/kg L-carnitine, respectively, for seven successive days. Then, except for the control group, the other four groups were transferred into the environment with ambient temperature of (39.5 ± 0.4 °C) and relative humidity of (13.5 ± 2.1%) for 2 h. The core temperature (Tc), mean arterial pressure (MAP), heart rate (HR) and serum and myocardial indexes were detected. Results: Compared with the heatstroke group, in the 100 mg/kg L-carnitine group, the Tc was significantly decreased, the MAP and HR were significantly increased, the serum creatine kinase, lactate dehydrogenase, alkaline phosphatase, aspartate aminotransferase, tumor necrosis factor and interleukin 1 levels were significantly decreased, the myocardial superoxide dismutase and glutathione peroxidase levels were significantly increased, the myocardial malondialdehyde level was significantly decreased and the cardiomyocyte apoptosis index and myocardial caspase-3 protein expression level were remarkably decreased (p 0.05). Conclusions: The L-carnitine pretreatment can alleviate the myocardial injury in heatstroke rats through reducing the inflammatory response, oxidative stress and cardiomyocyte apoptosis.(AU)