THE EFFECT OF HIGH-DOSE ANTENATAL VITAMIN-E ON HYPOXIA-INDUCED CHANGES IN NEWBORN RATS

The protective effects of high dose antenatal vitamin E on hypoxemia i n newborn rats were investigated. The subjects were 1-d-old Wistar rat s weighing 5-6 g which were born to mothers weighing 245-250 g. Three groups of rat pups, each consisting of eight newborn rats, were used: nontreated control group, hypoxic group, and vitamin E group. The moth ers of pups in the last group were given vitamin E (2000 mg/kg/d) ante natally on 3 consecutive days. Hypoxia was induced by breathing of a m ixture of 8% oxygen and 92% nitrogen for 3 h. Then pups were allowed t o inhale normal atmospheric air for 30 min. All rats were killed on th e first day of life after the procedure of hypoxia and reoxygenation. The brains, lungs, livers, intestines, and kidneys were studied bioche mically and histopathologically. The hypoxia-induced biochemical chang es were determined by measuring lipid peroxidation and myeloperoxidase activity. Vitamin E effectively inhibited hypoxia-induced lipid perox idation in liver and intestines, and decreased the levels of thiobarbi turic acid-reactive substances in brain. In agreement with lipid per o xidation, tissue associated myeloperoxidase activity was increased in liver, intestines, and kidneys, but not in brain and lungs, of the hyp oxic group. Histopathologic changes in intestines were epithelial sepa ration and submucosal polymorphonuclear leukocyte infiltration. In the liver, leukocyte infiltration was observed only near the portal areas . These changes were not observed in the vitamin E group. It was concl uded that high doses of antenatal vitamin E may protect the newborn ra t pups against hypoxia-induced tissue injury.