Postnatal treatment of human seminal plasma inhibin: gonadotropin and prolactin levels during the onset of puberty in the rat.

Plasma gonadotrophin and prolactin levels, pituitary and accessory sex organ weights were evaluated on day 40 in rats of either sex treated with human seminal plasma (HSP) inhibin on day 7, 15, 21 and 30 postnatally. HSP inhibin suppressed both FSH and LH but without any effect on plasma PRL levels. The weights of pituitary and accessory sex organs were significantly suppressed. These results indicate a role for inhibin in the postnatal gonadotrophin release and a possible direct action on the accessory reproductive organs in the rat.