Histamine stimulates prolactin release in norman men.

Histamine stimulates prolactin (PRL) and growth hormone (GH) release in the experimental animal. In order to evaluate the possible effect of histamine on these hormones in man, in our study, 9 normal volunteers underwent an intravenous histamine infusion (200 microgram in 15 min). Five of them also underwent an intravenous histidine infusion (200 microgram). Histamine induced a significant PRL release in 7 subjects, the maximum level reached being 36.2 +/- 12.09 ng/ml, while GH levels were not affected. Histidine was ineffective on both PRL and GH levels. It is known that histamine, administered peripherally, does not cross the blood brain barrier. This fact suggests that, in man, histamine stimulates PRL release by acting directly on the pituitary. In addition, since stressful situations may elicit both PRL and GH release, the fact that the latter was not affected by histamine, suggests that a mere stress-effect is not responsible for the PRL release observed in our subjects.