α-Tocopherol acetate significantly suppressed the increase in heart interstitial 8-hydroxydeoxyguanosine following myocardial ischemia and reperfusion in anesthetized rats

Abstract

The effect of α-tocopherol acetate, an aqueous form of α-tocopherol, on the increase in heart interstitial 8-hydroxydeoxyguanosine (8-OH-dG) levels following myocardial ischemia/reperfusion was investigated. A microdialysis probe was implanted in the left ventricular interstitial space of anesthetized rat hearts. Myocardial ischemia was induced by ligating the left anterior descending coronary artery. Levels of 8-OH-dG in microdialysates were analyzed via an on-line high-performance liquid chromatography system equipped with an electrochemical detector. The 8-OH-dG levels significantly increased (maximum 3.6-fold of increase relative to basal value) during the 60-min reperfusion stage following a 20 min ischemia. Administration of α-tocopherol acetate (20 mg/kg, intravenous, bolus) at 3 min prior to onset of reperfusion, significantly suppressed the reperfusion-induced increase in 8-OH-dG levels. These results suggested that one of the possible protective effect of α-tocopherol acetate was to reduce oxidative DNA damage during in myocardial ischemia and reperfusion.