Hyperprolactinaemic patients occasionally demonstrate
hirsutism and elevated levels of
DHA-S, a weak
androgen of adrenal origin. Abnormal adrenal function is frequently observed in hirsute patients. These observations prompted speculation that
prolactin may modulate normal adrenal secretion and that derangements of adrenal
androgen secretion may be due to abnormalities in
prolactin. In this study we examined the possibility that elevated
prolactin levels may be involved in the pathogenesis of hyperandrogenaemia in hirsute patients. However, basal
prolactin levels in hirsute women, with or without menstrual disturbances, 201 +/- 24.3 mU/l (mean +/- SE) and 192 +/- 24.3 mU/l respectively, were significantly suppressed below levels in normal women, 289 +/- 12.2 mU/l. The
prolactin responses to stimulation with TRH and to suppression with
L-dopa were also studied in hirsute patients. The
prolactin response to TRH (maximum increment or integrated response) was exaggerated significantly in hirsute women with menstrual disturbances when compared to normal women, to hirsute women with normal menses or to normal men. This abnormal response may have been due to elevated oestrone levels present in patients with oligomenorrhoea (318 +/- 49.5 pmol/l compared to 191 +/- 12.1 pmol/l in normal women and 161 +/- 15.5 pmol/l in hirsute women with normal menses, P less than 0.05). There were no abnormalities detected in the suppression of
prolactin in response to
L-dopa in any of these groups. These findings do not support a role for
prolactin in the pathogenesis of hyperandrogenaemia in hirsute patients. However, elevated
androgen levels in women may bring about suppression of basal
prolactin levels to values seen in normal men. (ABSTRACT TRUNCATED AT 250 WORDS)