Effect of α-Tocopherol on High Energy Phosphate Metabolite Levels in Rat Heart by 31P-NMR using a Langendorff Perfusion Technique

To examine the action of α-tocopherol on high energy phosphate compounds, a 31P-NMR technique was applied to perfused Langendorff rat hearts. Rats were treated with tocopherol acetate (25 mg/kg body wt i.p.) for 7 consecutive days. On the 7th days, the rat hearts were isolated for the Langendorff experiment. After 30 min of global ischemia the NMR signals of creatine phosphate and ATP in myocardium disappeared, and then recovered slightly in the reperfusion following ischemia. However, in the tocopherol-treated rat hearts, the restoration of high energy phosphate compounds occurred quickly after the beginning of reperfusion, although there was no significant difference in the destruction of high energy phosphate compounds during the ischemia. The α-tocopherol level in the myocardium was severely depleted by ischemia-reperfusion. In the α-tocopherol-treated animals, the α-tocopherol level in myocardium was still significantly higher than the control level at the end of 30 min of global ischemia . The heart mitochondrial respiratory function was simultaneously protected against ischemia-reperfusion injury. The role of α-tocopherol was discussed as a radical scavenger and membrane stabilizer against oxygen stress.