Impairment of the control of gonadotrophin secretion after oestrogen administration to adult female rats
Brown-Grant, K.; ter Haar, M.B.
Journal of Endocrinology 73(3): 497-505
1977
ISSN/ISBN: 0022-0795 PMID: 874400 DOI: 10.1677/joe.0.0730497Document Number: 434462
The possible occurrence of long-term changes in gonadotropin control mechanisms following the administration of estrogen to adult female rats was studied. Administration of 2.5 mg estradiol benzoate (OB) to normal female rats at 60 days of age did not result in failure of ovulation at 120 days of age but significant impairment of the LH levels in response to estrogen priming after ovariectomy were not affected in any of the experimental groups. The administration of a long-acting estrogen preparation (estradiol cyclopentyl propionate, 2.5 mg at 60 days of age) to normal female rats suppressed ovulation and depressed plasma LH and FSH concentrations for at least 90 days; anterior pituitary weights were greatly increased and plasma prolactin concentrations were very high.