ANDROGEN AND CORTISOL RESPONSES TO ACTH STIMULATION IN WOMEN WITH HYPERPROLACTINAEMIA

Abstract

SUMMARYBasal serum concentrations of androgens (testosterone and dihydrotestosterone) and dehydroepiandrosterone sulphate (DHAS) were measured in 7 normal and in 14 anovulatory women with raised serum prolactin. No patient had detectable skull x‐ray abnormalities. The mean DHAS, but not the androgens, were significantly higher in the women with hyperprolactinaemia (p < 0.01) and in 7 of the 14 the values were above the normal range which is 2.9–11.2 μmol/l. The 7 normal subjects and 9 of the women with hyperprolactinaemia were given ACTH (0.5 mg twice daily for four days). Cortisol and androgen concentrations in response to ACTH were not significantly different in the two groups, but the levels of DHAS (p < 0.001) were significantly higher over the four days in patients with hyperprolactinaemia. The concentrations of DHAS in these women were significantly higher by two days and continued to rise on day four of the test, but the concentration of androgens was greatest at two days as in the normal group.Treatment with bromocriptine to suppress plasma prolactin concentrations also lowered DHAS within 2–4 weeks, (p < 0.01) and the suppression was maintained for three months. Androgens initially increased significantly (p < 0.05) but by three months decreased again to the initial values.Taken together these results suggest that in the hyperprolactinaemic state biosynthesis by the Δ5 pathway to DHAS is favoured and there is partial inhibition of 3β‐ol‐dehydrogenase isomerase resulting in impaired conversion of Δ5 to Δ4 steroids.