title: [Nature of cytogenetic and morphologic disorders in rat oogenesis and embryogenesis induced by chloridin and 2,4,5-trichlorophenoxyacetic acid during the preovulatory phase of meiosis].
abstract: The effect of pyrimethamine (chloridine) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) on embryo survival, cleavage rate and frequency of chromosome aberrations when injected into female rats just before ovulation was studied. Pyrimethamine induced 70% of embryonic death at a dose of 5 mg/kg and 27%--at a dose of 2 mg/kg. 200 mg/kg of 2,4,5-T had no embryotoxic effect, while 400 mg/kg increased the embryo loss up to 48%. Pyrimethamine (5 mg/kg) and 2,4,5-T (400 mg/kg), injected intragastrically just before ovulation, significantly affected the cleavage rate in the four day rat embryos. The frequency of chromosome aberrations in ovulated oocytes at metaphase, II subjected to pyrimethamine and 2,4,5-T, reached 6--8% and exceeded the control value in 5--10 times.
mesh_terms: D015085:2,4,5-Trichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D002869:Chromosome Aberrations; D002970:Cleavage Stage, Ovum / Q000187:drug effects; D020964:Embryo Loss / Q000139:chemically induced*; D005260:Female; D005313:Fetal Death / Q000139:chemically induced*; D008540:Meiosis / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects*; D009866:Oogenesis / Q000187:drug effects; D010063:Ovum / Q000187:drug effects*; D011247:Pregnancy; D011739:Pyrimethamine / Q000633:toxicity*; D051381:Rats
chemical_list: D015085:2,4,5-Trichlorophenoxyacetic Acid; D011739:Pyrimethamine
vernacular_title: Kharakter tsitogeneticheskikh i morfologicheskikh narusheniĭ v oogeneze i émbriogeneze krysy, indutsiruemykh khloridinom i 2,4,5-trikhlorfenoksiuksusnoĭ kislotoĭ v predovuliatornoĭ faze meĭoza.