[Phenylalanine-4-hydroxylase and tyrosine aminotransferase activities in rat liver tissue under different vitamin E content in the organism]. / Fenilalanin-4-gidroksilaznaia i tirozinaminotransferaznaia aktivnosti v tkani pecheni krys pri razlichnoi obespechennosti organizma vitaminom E.

Enzymic activity of tyrosine aminotransferase is unchanged in subcellular fractions of the liver tissue of control, E-hypovitaminotic rats and of the same animals subjected to a single vitamin E administration. Enzymic activity of phenyl alanine-4-hydroxylase in the supernatant fraction determined in the incubation medium without biopterin in animals with E-hypovitaminosis is 39% lower than in the control rats. The coefficient of phenyl alanine-4-hydroxylase activation with biopterin in vitro in E-hypovitaminotic animals is thrice as high as that in the control rats. A single vitamin E administration produces a 1.8-fold decrease in the activation coefficient. The data obtained give reason to suggest the possible influence to vitamin E on the biopterin level in the liver.

[Effects of alpha-tocopherol derivatives on natural quinone levels in the tissues of vitamin E deficient rats]. / Deistvie proizvodnykh al'fa-tokoferola na soderzhanie prirodnykh khinonov v tkaniakh vitamin E-nedostatochnykh krys.

The effects of alpha-tocopherol and its derivatives (alpha-tocopherylquinone, its short-chained analog--alpha-tocopheronolactone--and short-chained alpha-tocopherylacetate) on the levels of ubiquinone, its cyclic isomer--ubichromenol--and vitamin E in the liver and heart of vitamin E-deficient rats were studied. After injection of alpha-tocopherol derivatives the levels of ubichromenol and ubiquinone in rat liver and heart were increased, while their ratio was decreased. alpha-Tocopheronolactone was found to exert the strongest action, which is probably due to its direct effect on ubiquinone metabolism in rat tissues.