Journal of Clinical Endocrinology & Metabolism, Vol 54, 849-853, Copyright © 1982 by Endocrine Society
Dynamic evaluation of prolactin secretion in essential hypertension: evidence against hypothalamic-pituitary dopaminergic dysfunction
AM Lengyel, JG Vieira, AR Chacra, JZ Abucham-Filho, MP Lima, AB Ribeiro and OL Ramos
Hyperprolactinemia has previously been noted in patients with essential
hypertension and it has been suggested that the increased PRL levels in
this condition may reflect reduced central dopaminergic activity. In the
present study, PRL secretion was evaluated in 17 patients with essential
hypertension and in 9 normal controls as an indirect index of
hypothalamic-pituitary dopaminergic activity. PRL levels were measured
basally, at night, and after TRH (200 micrograms, iv), metoclopramide (10
mg, orally), and L-dopa (500 mg, orally). Basal PRL levels were similar in
both groups [essential hypertension, 301.2 +/- 176.2 microunits/ml;
controls, 334.2 +/- 98.8 microunits/ml (mean +/- SD)]. No differences in
PRL levels were found after TRH, L-dopa, and metoclopramide or during sleep
between the 2 groups. When the patients were classified according to their
PRA, no differences were noticed in either basal levels or the patterns of
PRL response. It is concluded that PRL secretion is normal in patients with
essential hypertension, which could be indirect evidence against reduced
hypothalamic-pituitary dopaminergic activity in this disease. However,
minor abnormalities not detected by PRL measurements could be involved in
the pathogenesis of essential hypertension.
