title: Factor in urinary extracts from pregnant women that inhibit mouse oocyte maturation in vitro.
abstract: Mouse oocyte maturation inhibitory factors, on the basis of inhibitory activity of spontaneous germinal vesicle breakdown (GVBD) of denuded mouse oocytes in culture, were extracted and partially purified by reversed-phase resin adsorption and Sephadex G-100 and G-50 column chromatographies from the urine of pregnant women. Denuded oocytes obtained from ovaries of ICR mice underwent spontaneous GVBD by cultivation for 3 h in modified Krebs-Ringer's buffered solution, while this spontaneous GVBD was found to be inhibited by adding the final preparation (U-D-4) of urine. The inhibition was dose dependent, ranging from 0.6 to 10 micrograms protein/ml medium. Oocytes treated with U-D-4 and resuspended in control medium resumed GVBD. The molecular mass of U-D-4 was estimated to be less than 2,000 Da with gel filtration. Ether treatment failed to extract inhibitory factor(s) from U-D-4 and pepsin treatment inactivated U-D-4, indicating that inhibitory factor(s) in U-D-4 are peptide-like substances. The inhibitory effect of U-D-4 on spontaneous GVBD was partially reversed in the presence of naloxone, a potent opioid antagonist. U-D-4s obtained from urine samples of pregnant women, nonpregnant women, and men showed the inhibitory effect on spontaneous GVBD; however, the activity of U-D-4 obtained from pregnancy urine was significantly more potent than those of the other urine samples.
authors.affiliation: Department of Biochemistry, School of Clinical Pharmaceutical Sciences, Nagasaki University, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Sakakibara
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai
authors.forename: T
authors.initials: T
authors.lastname: Kohnoura
authors.forename: M
authors.initials: M
authors.lastname: Ishiguro
mesh_terms: D000818:Animals; D005260:Female; D006131:Growth Inhibitors / Q000494:pharmacology* / Q000652:urine*; D006801:Humans; D066298:In Vitro Techniques; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008813:Mice, Inbred ICR; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development; D010455:Peptides / Q000494:pharmacology* / Q000652:urine*; D011247:Pregnancy
chemical_list: D006131:Growth Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; C018355:intraovarian peptides