title: Effects of pure 2,4-dichlorophenoxyacetic acid on cultured rat embryos.
abstract: 2,4-dichlorophenoxyacetic acid (2,4-D), a plant growth regulator, has been used worldwide as a herbicide. Previously we evaluated the prenatal developmental effects of 2,4-D by feeding it to pregnant rats and found that it is maternally toxic and embryolethal, and it induces urogenital malformations in rat fetuses. In the study presented here, we investigated the effects of pure 2,4-D on rat embryos in whole embryo culture. Rat embryos on day 9.5 of gestation were cultured for 48 h at several concentration levels with pure 2,4-D (50-500 microg/mL). 2,4-D caused a concentration-related increase in the incidence of each malformation. Significant decreases in the number of somites were observed at a concentration of 100 microg/mL or more. At the concentration of 100 microg/mL, there was normal yolk sac circulation. This result suggests that 2,4-D has a detrimental effect on somite development and directly damages developing embryos.
authors.affiliation: Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Japan. kikky@cronos.ocn.ne.jp
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Sameshima
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Kobae
authors.forename: Djibril
authors.initials: D
authors.lastname: Fofana
authors.forename: Kouichi
authors.initials: K
authors.lastname: Yoshidome
authors.forename: Junichiro
authors.initials: J
authors.lastname: Nishi
authors.forename: Koichiro
authors.initials: K
authors.lastname: Miyata
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D046149:Embryo Culture Techniques; D004622:Embryo, Mammalian / Q000002:abnormalities / Q000187:drug effects*; D005260:Female; D006540:Herbicides / Q000633:toxicity*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid