VITAMIN-C, VITAMIN-E AND VITAMIN-A AND HEME OXYGENASE IN RATS FED METHYL FOLATE-DEFICIENT DIETS/

There is evidence that the development of hepatocarcinoma in rats fed a methyl-deficient diet is associated with oxidative stress. We invest igated, therefore, whether the tissue concentrations of the antioxidan t vitamins ascorbic acid (AA) and alpha- and gamma-tocopherol (T) are altered in methyl/folate deficiency, We also measured retinol concentr ations in tissues and hepatic mRNA expression of heme oxygenase (HO1). A 6% gelatin, 6% casein diet, devoid of choline and folate (CFD) was selected based on the high rate of tumor development in rats fed this diet. Spectrophotometric measurement of AA and HPLC determination of t issue T and retinol showed decreased concentrations of AA in blood; al pha- and gamma-T in lung, heart and plasma, alpha-T and retinol in liv er; retinol in lung; and increased expression of hepatic HO1 mRNA. Sim ilar alterations in tissue vitamin concentrations were found when the CFD diet devoid of niacin (CFND) was fed. Reducing alpha-T in the CFND diet (CFNED) further decreased hepatic alpha-T concentrations. These results show that chronic methyl/folate deficiency is associated with a compromised antioxidant defense system. (C) 1997 Elsevier Science In c.