Inhibition of Ovarian Aromatase by Prolactin In Vivo 1
- 1 September 1983
- journal article
- research article
- Published by Oxford University Press (OUP) in Biology of Reproduction
- Vol. 29 (2), 342-346
- https://doi.org/10.1095/biolreprod29.2.342
Abstract
Ovarian aromatase activity was inhibited by prolactin treatment in both cycling rats and immature gonadotropin-primed animals. Cycling rats were injected s.c. with prolactin (4 mg/kg BW) beginning on diestrus 1. Aromatase activity in the largest follicles on diestrus 2 and on proestrus was reduced relative to controls. None of the prolactin-treated animals had ovulated when examined on the expected estrus morning. In other experiments, the immature pregnant mare's serum gonadotropin (PMSG)-primed rat was used as a model for the cycling rat. Microsomal aromatase activity but not the activity of the C17-21 lyase was reduced in ovaries of animals injected with prolactin [6 IU (200 micrograms)/rat] 48 h after PMSG administration and sacrificed 4 h later. Furthermore, aromatase activity was significantly increased when endogenous prolactin was inhibited by bromocryptine (CB-154). The effect of LH treatment, on the other hand, was to increase both aromatase and lyase activities. However, prolactin pretreatment did not consistently prevent the LH-induced increase in aromatase activity. The results suggest that inhibition of ovulation by prolactin is mediated, at least in part, by direct inhibition of aromatase activity.This publication has 11 references indexed in Scilit:
- Prolactin Inhibits Pituitary Luteinizing Hormone-Releasing Hormone Receptors in the RatEndocrinology, 1982
- Human ovarian receptors to human prolactin: implications in infertilityFertility and Sterility, 1982
- Antigonadal Action of Prolactin: Further Studies on the Mechanism of Inhibition of Follicle-Stimulating Hormone-Induced Aromatase Activity in Rat Granulosa Cell Cultures*Endocrinology, 1982
- Divergent Effects of Prolactin on Estrogen and Progesterone Production by Granulosa Cells of Rat Graafian Follicles*Endocrinology, 1982
- Prolactin inhibits oestrogen synthesis in the ovaryNature, 1981
- Prolactin inhibition of estrogen production by cultured rat granulosa cellsMolecular and Cellular Endocrinology, 1980
- Ovarian Follicular Development during the Rat Estrous Cycle: Gonadotropin Receptors and Follicular Responsiveness1Biology of Reproduction, 1979
- The Effect of an Aromatase Inhibitor, 4-Hydroxy-4-Androstene- 3,17-Dione, On Estrogen-Dependent Processes in Reproduction and Breast Cancer11Endocrinology, 1977
- Studies on the mechanism of estrogen biosynthesis in the rat ovary–IThe Journal of Steroid Biochemistry and Molecular Biology, 1976
- CLINICAL AND ENDOCRINE FEATURES OF HYPERPROLACTINAEMIC AMENORRHOEAClinical Endocrinology, 1976