The causes of infertility in hyperprolactinemia

A study was made of function of the hypothalamohypophyseal system in women with infertility combined with hyperprolactinemia. Changes in the levels of prolactin, LH, FSH and TSH in response to the administration of releasing hormones (gonado- and thyroliberin) and metoclopramide (dopamine antagonist) were determined in 28 women with hyperprolactinemic amenorrhea and in 5 women with a normal menstrual cycle. Resistance of lactotrophs to functional tests was revealed. It grew with an increase in a prolactin level. On the contrary, a response of gonado- and thyrotrophs to functional tests grew with an increase in a degree of hyperprolactinemia. The authors arrived at a conclusion that stable hyperprolactinemia resulted from disorder of the receptor apparatus of lactotrophs with the resultant nonsusceptibility of the latter to an inhibitory effect of dopamine to prolactin secretion. Proceeding from their own and literature data, the authors propose for discussion a scheme of fertility disturbance in stable hyperprolactinemia.