Читать книгу Bovine Reproduction - Группа авторов - Страница 39

Prolactin (PRL) is known to enhance the effect of LH on spermatogenesis. The physiological importance of PRL in the regulation of Leydig cell function was first determined using three animal models [41, 42]: the golden hamster, where testicular regression can be induced by short photoperiod; hypophysectomized mice; and the hereditary dwarf mouse with congenital PRL deficiency and infertility. In all three models there is a deficiency in plasma concentrations of PRL and testosterone and testicular atrophy is evident. PRL therapy, on the other hand, stimulates spermatogenesis in the dwarf mouse and restores testicular function in the golden hamster; in hypophysectomized animals, PRL, in the presence of LH, induces spermatogenesis and restores plasma testosterone. In men, PRL has an important role in the control of testosterone and reproductive function [49]. At very high concentrations (hyperprolactinemia), PRL has an antigonadal effect in men, inhibiting testicular function, and is associated with hypogonadism [50].