INFLUENCE OF PROGESTERONE UPON THE FERTILITY OF GONADOTROPHIN-TREATED FEMALE RABBITS

Publisher Website
Google Scholar
Abstract
A relation between the stage of the reproductive cycle at the time of treatment with gonadotrophins and the fertility of the artificially ovulated ova has been reported in rabbits (Murphree, in press), cattle (Zavadovskii et al., 1935; Casida et al., 1940, 1943) and sheep (Murphree et al., 1944). Females treated at a time when the ovaries contain functional corpora lutea have shown little or no fertility, whereas good fertility has been shown by those females treated while in the follicular phase of the sexual cycle. Although there is evidence suggesting a relationship between the presence of corpora lutea and infertility, no adequate analysis of the endocrine basis for this phenomenon has been made. The previous studies have usually involved treatments which produced superovulation and the preparations used for the ovulating stimulus (unfractionated or luteinizing extracts of the pituitary gland injected intravenously) undoubtedly contained rather large amounts of the hormones necessary for the production of corpora lutea.