[Direct effect of prolactin on the ovary by monolayer culture of human luteal cells].

In order to elucidate the mechanism of anovulation and luteal insufficiency that occur in hyperprolactinemia, the direct effect of prolactin (PRL) on luteal cells in vitro was investigated using human luteal cells in a monolayer cell culture. 1) The direct effect of PRL (that was kindly provided by the National Institute of Arthritis, Metabolism and Digestive Diseases) as seen in the production of P was such that when PRL concentrations were 1 through 100ng/ml the luteal stimulatory action was demonstrated, but in concentrations above 100ng/ml the stimulatory action was attenuated, and at 1 microgram/ml inhibitory effects were observed. 2) There was no significant difference between the PRL-added group and non-added group on the production of E2 and 17OHP. 3) Production of P in the HCG 100ng group increased to about 4 times that of the non-added group. Production of P in the group with simultaneous addition of PRL 1 microgram-HCG 100ng also showed a similar degree of increase. From the above, it is concluded that PRL alone exerts a direct effect on luteal cells that is luteotropic and luteolytic, depending on the different concentrations of PRL. These facts suggested that the direct inhibitory effect of PRL on the ovary was one of the causes of anovulation and luteal insufficiency during hyperprolactinemia in vivo.