Estradiol potentiates antiarrhythmic and antioxidative effects of intermittent hypoxic rat heart

AIM: To study the effects of estradiol (Est) on antiarrhythmic and antioxid ative effects of intermittent hypoxia in rat heart. METHODS: Ligating and l oosening the coronary artery of rat to induce ischemic and reperfusion arrh ythmias, using arrhythmia score (AS) to evaluate the arrhythmias, measuring the activity of superoxide dismutase (SOD) and the content of malondialdeh yde (MDA) in myocardium. RESULTS: AS of arrhythmia induced by ischemia and reperfusion in intermittent hypoxia 28-d group (IH28) and in intermittent h ypoxia with Est group (IH14-Est) are lower than that in control group (CON) , respectively. AS of ischemic arrhythmia but not reperfusion arrhythmia in Est treated group (ESTG) was lower than that in CON. No si,significant dif ference in AS of ischemia and reperfusion existed among CON, vehicle group (VEH), and intermittent hypoxia 14-d group (IH14). The activity of SOD was higher and the content of MDA was lower in IH28 and in IH14-Est compared wi th that in CON. No significant difference of the activity of SOD and the co ntent of MDA existed among CON, VEH, IH14, and ESTG. CONCLUSION: Est potent iated the antiarrhythmic and antioxidative effects of intermittent hypoxia on rat heart.