STEROIDOGENIC EFFECTS OF LUTEINIZING HORMONE AND PROLACTIN ON THE RAT OVARY IN VIVO

Abstract

SUMMARY: Progesterone and 20α-dihydroprogesterone were measured in the ovarian venous blood of rats in early pro-oestrus, late dioestrus, day 5 of pseudopregnancy, and in androgen-treated animals with persistent oestrus. Little progesterone was secreted in early pro-oestrus or persistent oestrus (0·1 μg./hr.), but the secretion rose in dioestrus (2·1 μg./hr.) and in pseudopregnancy (7 μg./hr.). The 20α-dihydroprogesterone secretion was low in the persistent oestrous group; in all the other groups it was 1·5–3 μg./hr. Treatment with luteinizing hormone increased progesterone secretion within 30 min. in pro-oestrus and persistent oestrus, had no significant effect in dioestrus, and depressed it markedly in pseudopregnancy. It appeared to have no significant effect on 20α-dihydroprogesterone secretion except during pseudopregnancy, when it was depressed. Treatment with prolactin produced no effect within 30 min.in pro-oestrous, dioestrous or pseudopregnant animals.