Abstract: | 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. |