No abstract

The cardiovascular disease and sudden death due to the occlusion of coronary artery increases in women after menopause. In this study, it was aimed to research the effect of genistein that has been used to decrease the symptom of menopause in women, on the ischemia reperfusion induced arrhythmias. 64 Female and 12 male, 6-7months old Sprague Dowley rats were used in this study. Genistein was applied daily for four weeks in 100ug/kg dose intraperitoneally in one group and acutely in other group, before reperfusion in 1mg/kg dose intravenously. Six minutes myocardial ischemia were produced by the ligation of ramus interventricularis branch of left coronary artery (LAD) and six minutes of reperfusion by releasing of this artery. The type and duration of arrhythmias and the blood pressure recorded in every group during ischemia and reperfusion were analyzed and compared by using one-way ANOVA test and the incidence of arrhythmia and the survival rate by Ki square test. Genistein had no effect on the ischemia and reperfusion induced arrhythmias in male and ovariectomized female rats.

The number of ATP-dependent potassium channels in myocardial cells has been previously shown to change depending on gender and age. Different effects of the ATP-dependent potassium channel blocker, glybenclamide and ATP-dependent potassium channel opener, pinacidil on ischemia or reperfusion-induced arrhythmia observed in various research might depend on different ages and genders of the animals used. The aim of this study is to research the effect of ATP-dependent potassium channel modulators on ischemia-induced arrhythmia in animals of different ages and genders. Sprague-Dawley rats of different ages and genders were used in this study. Ischemia was produced by the ligation of the left coronary artery for 30 min. Electrocardiogram (ECG), blood pressure, infarct area and blood glucose were determined during the 30 min of ischemia. An arrhythmia score from an ECG recorded during 30 min of ischemia was determined by examining the duration and type of arrhythmia. Different effects of glybenclamide and pinacidil on the arrhythmias were observed in male and female young and middle-age rats. Pinacidil decreased the infarct zone in younger female rats, but differences in the type and length of ischemia-induced arrhythmias between females and males disappeared in older age. The results of this study showed that the effect of ATP-dependent potassium channel modulators on ischemia-induced arrhythmia changed due to the age and gender of rats.

This study examined the effect of yohimbine alone and in combination with glibenclamide on ischemia and reperfusioninduced arrhythmias in diabetes. Six minutes of ischemia were produced in 1-week diabetic rats by ligation of the left coronary artery, and 6 min of reperfusion were produced by releasing the artery. A dose of 5 mg/kg of yohimbine and glibenclamide was administered for 7 days prior to the coronary ligation. The blood pressure, heart rate, and arrhythmia were determined from the recorded ECG during the 6 min of ischemia and reperfusion and then compared using a one-way ANOVA statistical program and the chi-square test. The score of arrhythmia calculated from the type and duration of arrhythmia decreased in the diabetic rats (3.5 ± 1.69 in control, 1.7 ± 0.81 in diabetes group). The arrhythmia score returned to the control value in the rats that were given a combination of yohimbine and glibenclamide (3 ± 1.73). Yohimbine is used in the treatment of erectile dysfunction; glibenclamide is used as an antidiabetic drug in diabetic patients and may be a risk factor in the increase of ischemia reperfusion-induced arrhythmias.