Regulation of ovarian follicle atresia.
The majority of ovarian follicles undergo atresia, a hormonally controlled apoptotic process. Monitoring apoptotic DNA fragmentation provides a quantitative and sensitive endpoint to study the hormonal regulation of atresia in ovarian follicles. During follicle development, gonadotropins, together with local ovarian growth factors (IGF-I, EGF/TGF-alpha, basic FGF) and cytokine (interleukin-1 beta), as well as estrogens, activate different intracellular pathways to rescue follicles from apoptotic demise. In contrast, TNF-alpha, Fas ligand, presumably acting through receptors with a death domain, and androgens are atretogenic factors. These diverse hormonal signals probably converge on selective intracellular pathways (including genes of the bcl-2 and ICE families) to regulate apoptosis. With a constant loss of follicles from the original stockpile, the ovary provides a unique model for studying the hormonal regulation of apoptosis.
Kaipia
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A
Department of Gynecology and Obstetrics, Stanford University School of Medicine, California 94305-5317, USA.
Hsueh
A J
AJ
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D005260:Female; D005496:Follicular Atresia / Q000502:physiology*; D006728:Hormones / Q000502:physiology; D006801:Humans; D010053:Ovary / Q000166:cytology; D010063:Ovum / Q000502:physiology
D006728:Hormones