Prolactin Receptors in Mouse Liver: Species Differences in Response to Estrogenic Stimulation

Abstract

SummarySerum PRL and hepatic PRL receptors were measured in intact and OVX mice and OVX mice given several doses of EB, OVX significantly increased PRL binding in the liver of female mice, and EB reduced receptors to intact or below intact levels. It was concluded that estrogen decreases PRL receptors in the liver of female mice. This is a striking contrast to the stimulatory effect of estrogen on hepatic PRL receptors in male and female rats. EB elevated serum PRL in OVX mice, but since other investigators reported that PRL does not alter hepatic PRL receptors in female mice, it appears likely that estrogen reduced PRL binding sites by a direct effect on the liver. However, an indirect effect cannot be excluded. In male mice, estrogen increased PRL receptors in the liver as in male rats.The present data demonstrate important species differences between female rats and female mice in estrogenic control of hepatic PRL receptors. Moreover, the inhibitory effect of estrogen in female mice, and its stimulator...