title: Steroidogenic activity and ultrastructural observation of atretic follicles in the cycling hamster ovary.
abstract: In mature hamster ovaries, many follicles undergo atresia and this atretic change occurs in any estrous day. In this study, the localization of enzymes involved in estrogen biosynthesis, Bromodeoxyuridine (BrdU) incorporation, and Proliferating Cell Nuclear Antigen (PCNA) were immunohistochemically examined in the atretic follicles always provided with an atrum variable in size. Moreover, the granulosa cells from the atretic follicle in various but parallel stages of development were examined by scanning and transmission electron microscopes. Very early morphological signs of atresia in these follicles was the pyknotic change of a few granulosa cells lining the antral cavity. In this kind of follicles, the number of BrdU incorporating granulosa cell was decreased and the immunoreactivity of PCNA and aromatase was gradually decreased. Even in the early stage of atresia, some granulosa cells showed a remarkable morphological change characteristic of apoptosis as revealed by scanning and transmission electron microscopy.
authors.affiliation: Department of Anatomy III, Osaka University Medical School, Suita-city, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoshinaga-Hirabayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Osawa
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000493:pharmacokinetics; D004967:Estrogens / Q000096:biosynthesis*; D004971:Estrus / Q000502:physiology*; D005260:Female; D005496:Follicular Atresia / Q000378:metabolism*; D006107:Granulosa Cells / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D051379:Mice; D008854:Microscopy, Electron; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
chemical_list: D004967:Estrogens; D018809:Proliferating Cell Nuclear Antigen; D001973:Bromodeoxyuridine