The influence of vitamin E and dihydrolipoic acid on cardiac energy and glutathione status under hypoxia-reoxygenation.

The combination of vitamin E supplementation with dihydrolipoic acid perfusion synergistically improves cardiac functional recovery during post-ischemic reperfusion or post-hypoxic reoxygenation of the rat heart. To elucidate the mechanism of this effect, isolated rat hearts were perfused using a working heart system. In hearts perfused with a buffer containing dihydrolipoic acid, ATP levels were significantly higher than those of hearts perfused without addition of dihydrolipoic acid during 90 min of reoxygenation following 30 min of hypoxia. Cardiac tissue glutathione status measured in hearts after perfusion experiments showed significant elevation of reduced glutathione in vitamin E supplemented normoxic rat hearts without hypoxia. Significant elevation of oxidized glutathione was observed in dihydrolipoic acid perfused heart after hypoxia-reoxygenation. It is concluded that vitamin E and dihydrolipoic acid exert separate and synergistic effects in the protection of the hypoxic-reoxygenated heart.