[Prolactin in male reproduction].

Prolactin (PRL), a peptide hormon from the hypophysis, becomes more interesting, since it can be determined by radioimmunassays. The release of prolactin is controlled by two not yet identified factors, the prolactin-releasing-factor and the prolactin-inhibiting-factor. The latter predominantes. Many pharmacological substances can alter the release. The normal serum levels in the man are 6-13 ng/ml. Prolactin affects many organs, f.e. kidney, mamma, ovary, testis, hepar and skin. For clinical tests the raise in the serum levels after TSH or chlorpromacin and the drop after application of 2-brom-alpha-ergocryptin is used. Increased serum levels are found in patients with prolactin-producing tumors. In the male this is followed by disturbances of the sexual potency. Relations between prolactin and male infertility of gynecomastia are not yet known.