[Role of enzymes of dopamine metabolism in the regulation of prolactin and thyrotropin secretion in hyperprolactinemia].

Altogether 24 women with the syndrome of hyperprolactinemia (SH), including 5 patients with significant PRL hypersecretion against a background of macro- and microprolactinemia, and 19 women with normoprolactinemic galactorrhea were investigated. The activity of dopamine-B-hydroxylase (DBH) and monoamino oxidase (MAO) (the key enzymes of dopamine metabolism) was determined by spectrophotometry. A different time course of secretion of PRL and TSH in metoclopramide testing was revealed in the patients with regard to the level of basal prolactinemia. The determination of MAO and DBH activity made it possible to estimate in more detail the state of dopaminergic control of PRL and TSH secretion in the syndrome of hyperprolactinemia.