[Functional interrelations of monoamines, thyrotropic hormone and thyroid hormones in hyperprolactinemia]

Functional interrelationships of serotonin, dopamine, prolactin, TRH and thyroid hormones in patients with hyperprolactinemia were studied. Altogether 26 patients with amenorrhea in hyperprolactinemia without clinical signs of disorder of thyroid function were examined. The levels of serotonin and dopamine were determined by spectrofluorimetry, the level of hormones was determined by a radioimmunoassay. An increase in the level of serotonin and a decrease in the level of dopamine in all the patients, a decrease in TRH and T4, and an increase in T3 were noted. The levels of monoamines, TRH and thyroid hormones showed correlation. It has been concluded that disorder of the monoaminergic mechanisms of regulation creates conditions for the rearrangement of hormonal interrelationships in the neuroendocrine functional system and determines the involvement of the hypophyseothyroid system in the pathological process. Therefore patients with hyperprolactinemia are at risk of developing thyroid functional disorders.