title: Ovulation in the isolated perfused rat ovary as documented by intravital microscopy.
abstract: Surface cell changes at the apices of preovulatory follicles and ovulations were documented in isolated perfused ovaries from immature rats treated with pregnant mare serum gonadotropin (20 IU) and 48 h later with human chorionic gonadotropin (hCG) (10 IU). A video camera coupled to an inverted microscope and a video recorder captured the preovulatory and ovulatory events at a cellular level. At around 8 h post-hCG, the follicular apex changed from a smooth and optically homogeneous appearance into a rough surface with bleb formation and extrusions of single cells through minute perforations (early stigma formation). At approximately 10 h, a sticky material formed a basketlike structure with trapped cells (late stigma formation). At 12 to 15 h, ovulation took place at a constant speed and with no contractions of the follicular wall. This indicates that ovulation can occur with no visible circumfollicular muscular activity. Furthermore, the observations of a leakage of cells over an extended period of time indicates that the follicular wall is partly digested several hours before ovulation occurs.
authors.affiliation: Department of Obstetrics and Gynecology, University of Göteborg, Sweden.
authors.forename: C O
authors.initials: CO
authors.lastname: Löfman
authors.forename: M
authors.initials: M
authors.lastname: Brännström
authors.forename: P V
authors.initials: PV
authors.lastname: Holmes
authors.forename: P O
authors.initials: PO
authors.lastname: Janson
mesh_terms: D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D008853:Microscopy / Q000379:methods*; D010053:Ovary / Q000187:drug effects / Q000502:physiology*; D010060:Ovulation; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains; D014741:Video Recording
chemical_list: D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine