[Protective effects of orientin on myocardial ischemia and hypoxia in animal models].

To study the protective effects of orientin against myocardial ischemia and hypoxia in rats. The protective effect of orientin against myocardial ischemia and hypoxia was observed in mice by recording their survival time under closed normobaric hypoxia and time of cardiac electric disappearance due to trachea clamping, in rabbits by evaluating arachidonic acid (AA)-induced blood platelet aggregation, in guinea pigs by measuring the coronal flow in the isolated heart and in SD rats with myocardial ischemia induced by pituitrin injection. Orientin (1, 2, 4 mg/kg) significantly prolonged the survival time of mice under closed normobaric hypoxia and the gasping duration induced by decapitation. Orientin at concentrations of 3, 10, and 30 micromol/L also inhibited AA-induced blood platelet aggregation in rabbits and increased coronal flow in the isolated heart of guinea pigs. At 0.75, 1.5, and 3.0 mg/kg, orientin significantly antagonized pituitrin-induced ECG changes. Orientin may offer protection against myocardial ischemia and hypoxia in animal models in dose-dependent fashions.