FOETAL GROWTH RETARDATION AND MORTALITY BY CHRONIC DEXAMETHASONE ADMINISTRATION TO PREGNANT RATS

Abstract

University of Paris, Endocrinology Laboratory, 91405 Orsay, France (Received 24 February 1976) Liggins (1973) provided convincing evidence of the role of glucocorticoids in the maintenance of parturition in the ewe. By appropriate infusions of various doses of dexamethasone, the time of parturition can be advanced by several weeks (Liggins, 1969; Bosc, 1972). The following experiments were performed to observe the effects of two doses of dexamethasone, administered to pregnant rats, upon foetal growth up to parturition. These effects of dexamethasone were also compared with those of cortisol and adrenocorticotrophin (ACTH). Female Sherman rats (200–300 g body wt) were impregnated by keeping one male with seven females overnight (Parvez, Parvez & Youdim, 1975). The females were palpated 12 days later and the pregnant ones caged singly. Normally, parturition occurs between 21·5 and 22 days of gestation. The pregnant rats were divided into several groups. The first two groups received daily s.c.