ADRENAL INVOLVEMENT IN THE TIMING OF PUBERTY IN FEMALE RATS: INTERACTION WITH SERUM PROLACTIN LEVELS
- 1 November 1978
- journal article
- research article
- Published by Bioscientifica in Acta Endocrinologica
- Vol. 89 (3) , 590-598
- https://doi.org/10.1530/acta.0.0890590
Abstract
Female Sprague-Dawley derived rats were either sham-operated or adrenalectomized at 20 days of age. Treatment of separate groups of rats with progesterone, corticosterone or prolactin was started at 21 days of age, and was continued until the day of vaginal opening. Similarly treated rats were decapitated at 25, 29 and 33 days of age and at the day of vaginal opening and the sera were collected from each animal and assayed for prolactin, LH [lutropin] and FSH [follitropin]. All rats were decapitated between 16:00-18:00 h. Adrenalectomy, as previously reported, significant delayed the day of vaginal opening. Prolactin treatment advanced the day of vaginal opening in intact rats and it restored the day of vaginal opening in adrenalectomized rats to that of intact control rats. Progresterone treatment always delayed the day of vaginal opening in intact rats. It caused an even greater delay in vaginal opening than adrenalectomy alone. Corticosterone treatment was able to reverse the effect of adrenalectomy but had no effect on vaginal opening in intact rats. In intact rats serum prolactin levels rose steadily until the day of vaginal opening. Adrenalectomized and intact rats treated with progesterone had significantly decreased serum prolactin levels. In adrenalectomized corticosterone treated rats serum prolactin levels were significantly increased at all ages measured when compared to the untreated rats. The FSH and LH levels showed no significant changes during any of these experimental procedures. Approximately 50% of the rats showed LH peaks on the day of vaginal opening as well as an increase in FSH. A prolactin-adrenal interaction for the timing of the onset of puberty is indicated in immature rats, assuming that the day of vaginal opening in association with increased gonadotropin levels is an indicator for the occurrence of puberty.This publication has 1 reference indexed in Scilit: