Pregnant rats were injected with busulfan on day 12 or 18 of gestation and the ovaries of 5-and 10-day-old neonates were compared with control ones in terms of 1) folliculogenesis, 2) production of estradiol-17\g=b\and estrone in vitro, 3) aromatase and 3 \ g = b \ \ x = r e q -\ hydroxysteroid dehydrogenase/isomerase (3\g=b\-HSD) activities, and 4) anti-m\l=u"\llerianhormone. Injection of busulfan on day 12 led to a reduction in the number of germ cells and follicles, delayed the maturation of antral follicles and lowered estrogen production and aromatase and 3\g=b\-HSDactivities. Anti-m\l=u"\llerianacti-vity, present in ovaries from 10-day-old controls, was also depressed in busulfan-treated rats. No obvious effects were observed when busulfan was injected on day 18. Estrogen biosynthesis could be stimulated by gonadotropins at day 10 post-partum, indicating the presence of functional receptors to LH and/or FSH. These relationships are interpreted as indicating that ovarian cells retain their capacity to respond to hormonal challenge despite the morphological impairment induced by busulfan. Other factors which possibly interfere with ovarian activity in busulfan-treated rats are discussed.Biosynthesis of estrogens by rat ovaries starts at the end of the first week after birth (Lamprecht et al. 1976) just as secondary follicles possessing two or more layers of follicle cells are organized (Slater & Dornfeld 1945). Ovarien estrogen biosynthesis has been demonstrated to require both granulosa and theca cells (Falck 1959;Savard et al. 1965). Moreover, intact follicle walls have been shown to produce more estrogen than co-cultures of the two kinds of cells (Takahashi et al. 1984).In the course of development, follicle cells are first arranged in a single layer around each oocyte, so germ cells seem to act as differentiating centres for folliculogenesis. Perturbation in folli¬ culogenesis can be induced when germ cells are destroyed during the fetal period. The secretory activity of ovaries sterilized by fetal irradiation has been suspected to be lowered (Beaumont 1962) and no cells with the ultrastructural characters of differentiated steroid-forming cells were found in ovaries sterilized with busulfan during fetal life, except where oocytes survived and organized fol¬ licles (Merchant-Larios 1976). The present study was performed to investigate estrogen biosynthesis, aromatase and 3ß-hydroxysteroid dehydrogenase/isomerase (3ß-HSD) acti¬ vities, and responsiveness of the ovary to gonado¬ tropins in relation to folliculogenesis. Anti-miil¬ lerian hormone (AMH) activity, detected in the follicular fluid of mature bovine ovaries (Vigier et al. 1984), was also measured. This study focused on infantile ovaries from rats injected with busul¬ fan in fetal life.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.