Lipid peroxidation in newborn rabbits: Effects of oxygen, lipid emulsion, and vitamin E

Abstract

The extent of in vivo lipid peroxidation and the in vivo antioxidant effects of α-tocopherol and α-tocopheryl acetate were studied in newborn rabbits exposed to one of two oxidant stresses: hyperoxia (FIo2 >0.9) or parenteral lipid emulsion infusion. Lipid peroxidation was monitored by measurement of expired ethane and pentane, tissue thiobarbituric acid (TBA) reactants, and tissue lipid peroxides. Seventy-two h of hyperoxia did not increase any of the parameters of lipid peroxidation although mortality was higher in oxygen exposed animals. α-Tocopherol (100 mg/kg, intravenous) lowered expired hydrocarbons and tissue TBA reactants, but raised liver lipid peroxides in both air and hyperoxia exposed pups. Infusion of soybean oil emulsion increased production of ethane and pentane, liver TBA reactants, and lung lipid peroxides. Both α -tocopherol and α -tocopheryl acetate prevented the soybean oil emulsion induced increase in volatile hydrocarbons, α-Tocopherol (100 mg/kg, intravenous) administration also prevented the increase in liver TBA reactants and lung lipid peroxides. In identically treated animals, α-tocopheryl acetate administration decreased liver TBA reactants but had no effect on lung lipid peroxides. We conclude that α-tocopherol reduces lipid peroxidation in newborn rabbits including animals exposed to hyperoxia or infused with lipid emulsions. α-Tocopheryl acetate results in lower tissue α-tocopherol concentrations and is less effective as an antioxidant in lipid emulsion infused rabbits. © 1986 International Pediatric Research Foundation, Inc.