[Vitamin B 12 metabolism and the status of sulfhydryl groups in protein-choline deficiency in rats. Effects of methyl- and adenosylcobalamins].

The effect of low protein choline-deficient diet on total vitamin B12 content and individual cobalamin level in the blood serum and liver of rats was determined. Moreover the total and non-protein SH-group content and glutathione transferase activity in the liver of rats were studied. Total cobalamin content increased in the blood serum, but it did not change in the liver of rats fed choline-deficient low protein diet. Total and non-protein SH-group level as well as glutathione transferase activity in the liver decreased significantly. The causes of changes revealed are discussed. Methylcobalamin (but not adenosylcobalamin) administration normalized individual cobalamin level in the blood serum. Administration of both methylcobalamin and adenosyl-cobalamin resulted in total SH-group content restoration whereas non-protein SH-group level and glutathione transferase activity were restored only in methylcobalamin-treated rats.