Sıçanlarda iskemi-reperfüzyonla uyarılan aritmiler üzerine cinsiyet farklılığının ve pinasidil'in (ATP duyarlı potasyum kanal açıcısı) etkisi

ABSTRACT THE EFFECT OF GENDER DIFFERENCES AND PINACIDIL (ATP SENSITIVE POTASSIUM CHANNEL OPENER) ON THE ISCHEMIA - REPERFUSION INDUCED ARRHYTHMIAS IN RATS Suveren Tiryaki, Eylem M.Sc, Department of Biology Supervisor : Prof. Dr. Ömer BOZDO?AN January 2004, 59 pages KAtp channels play important roles in the generations of ischemia- reperfusion induced arrhythmias. There are still controversy about the opening or closing of the channels involve in the suppression of the arrhythmia. Since the number of KAtp channel is more in female, arrhythmic response to the reperfusion may be different in females. There are a few study indicating the effect of KAtp channel opening on the arrhythmias following coronary ligation in female. That is why, in this study the effect of gender differences on reperfusion induced arrhythmia and the role of the Katp channel opening was researched. Seventeen male and eighteen female rats weighing 210-280 gr in 6-8 months old were used in this study. Myocardial ischemia was produced by ligation of LAD and reperfusion by releasing of this artery. Pinacidil was givenintravenously in a dose of 1mg / kg, 10 min. before coronary artery ligation. Electrocardiogram (ECG) and arterial blood pressure were recorded during ischemia and reperfusion. The total length of arrhythmia, VF and VT observed following ligation and reperfusion were significantly low in female than males (P < 0.05). Pinacidil increased arrhythmia in female, but oppositely decreased arrhythmia in male. Arrhythmia score was significantly decreased in pinacidil treated male rats (P < 0.05) ; 3.7 in control and 2.0 in pinacidil treated group. As a result, opening of Katp channel was not effective to decrease arrhythmia in female, but decreased arrhythmia in male. This opposite effect may be derived from more Katp channel found in female. Opening of the channel by pinacidil in male may decrease electrical inhomogenity between ischemic and nonischemic region and may lead to the decreased arrhythmia. Key words: Coronary Ligation, Ischemia - Reperfusion, Arrhythmia, Gender, Pinacidil. n