[Dopaminergic regulation of the hypothalamo-hypophyseal system in patients with hypophyseal adenomas]

A study was made of the state of the hypothalamohypophyseal system in patients with different types of chromophobe adenoma. Altogether 62 patients were examined using metoclopramide and Parlodel tests (38 patients were with somatotropinoma, 13--with prolactinoma, 11--with somatotropinoma with hyperprolactinemia). The time course of STH, PRL and TSH secretion in the blood was investigated. Dopaminergic blockade in the Metoclopramide test was shown to cause no change in the time course of PRL secretion in patients with prolactinomas, and a PRL reaction in patients with somatotropinomas and adenomas with PRL and STH hypersecretion was sharply decreased. A paradoxical STH reaction (a decrease) in somatotropinomas and considerable disorders in the type of PRL and TSH secretion in all forms of adenomas was defined in the Parlodel test (a dopaminergic agonist). The results obtained suggest considerable disorders in the dopaminergic regulation of the hypothalamohypophyseal system of patients with chromophobe adenomas and the efficacy of the metoclopramide and Parlodel tests in the differential diagnosis of these conditions.