Vitamin E reduces glucocorticoid-induced growth inhibition and lipid peroxidation in rats.
This experiment was conducted to study the effects of vitamin E on growth inhibition and lipid peroxidation in rats treated with different levels of corticosterone (CTC). Rats (Sprague-Dawley strain, 5 weeks of age) were divided into two groups: control group receiving a basal diet containing 60 mg DL-alpha-tocopheryl acetate/kg diet, and vitamin E group receiving the same diet supplemented with 5,000 mg tocopherol. After 6 days, rats of both diet groups were further divided into three groups by dose levels of CTC treatment (0, 25, and 100 mg CTC/kg body weight/d). CTC was administered to the rats by subcutaneous injection for 4 d. Growth was dose-dependently inhibited by the CTC treatment. Feeding the vitamin E diet significantly (p < 0.05) improved growth retardation. Feed efficiency was lowered by CTC treatment, while this was significantly (p < 0.05) minimized by feeding the vitamin E diet. Lipid peroxidation (TBARS) in the liver was elevated by the CTC treatment (p < 0.001) when the rats were fed the basal diet. The increment in TBARS was significantly (p < 0.001) reduced by vitamin E. The activities of glutathione S-transferase (GST) and superoxide dismutase (SOD) were significantly reduced by the CTC treatment in a dose-dependent manner in both dietary groups. Feeding vitamin E significantly (p < 0.001) improved the reduction in GST activity. The SOD activity showed some tendency. The present results demonstrate the effectiveness of vitamin E in improving growth retardation in glucocorticoid-treated rats and suggest that reductions in increased lipid peroxidation due to CTC may be an important factor of the action of vitamin E.
Department of Biochemical Science & Technology, Faculty of Agriculture, Kagoshima University, Japan.
A
A
Ohtsuka
T
T
Ohtani
H
H
Horiguchi
H
H
Kojima
K
K
Hayashi
D000818:Animals; D000975:Antioxidants; D003345:Corticosterone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004032:Diet; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006128:Growth / Q000187:drug effects*; D007279:Injections, Subcutaneous; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000737:chemistry; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D003345:Corticosterone