The effect of histamine stimulation and H2 -receptor inhibition on the pituitary prolactin and ACTH release and on cortisol secretion in human males.

The effects of histamine (HA) on prolactin (PRL), ACTH, and cortisol secretion in human males were investigated. Specific H2 -receptor blockade caused an immediate and significant PRL release, while specific H2 -receptor stimulation (HA and mepyramine) was without effect on PRL secretion. HA significantly stimulated both ACTH and cortisol secretion, and this stimulation was probably mediated through H2 -receptors, H2 -receptor blockade caused a late, but significant ACTH release. This release was not accompanied by a release of cortisol, and might therefore be due to a spontaneous oscillation in ACTH secretion. The results support the theory that HA acts as a modulator of human ACTH secretion. A similar effect on PRL secretion as postulated by others could not be confirmed in this study.