[Effect of triiodothyronine and methylthiouracil on the enzymatic activity of biogenic amine metabolism in rat brain synaptosomes].

Triiodothyronine injections are shown to lower DOPA decarboxylation and 5-hydroxytryptophan decarboxylation activity and also to decrease the intensity of serotonin and norepinephrine oxidative deamination in the rats' brain synaptosomes. Hypothyroidism produced by 6-methylthiouracil administration was accompanied by intensification of the DOPA-decarboxylase activity and monamine oxidase transformation into serotonin and norepinephrine with no parallel occurring essential changes in the 5-hydroxytryptophan decarboxylation.