[Age-related changes in thyroxine regulation of the NADPH-dependent oxidative system in rat liver microsomes].

Age peculiarities of the thyroxin effect on oxidative microsome system are manifested at the level of different links of NADPH-dependent chain of electron transfer and are most pronounced relative to changes in the content of cytochrome P-450 and demethylase activity, which get considerably reduced with hyperthyrosis in the middle age. The aniline hydroxylase activity somehow increases with hyperthyrosis in young immature animals and is practically unchanged in adult and old ones. It is supposed that age peculiarities of the thyroid hormone action on the oxidation system in microsomes are determined to a consideralble extent by the level of androgens and depend on age changes in the reproductive function of the organism.