title: Micronucleus formation in 3-day mouse embryos associated with maternal exposure to chlorpyrifos during the early preimplantation period.
abstract: Chlorpyrifos, an organophosphate pesticide, was evaluated for its ability to induce cytogenetic damage in preimplantation embryos after maternal exposure. Pregnant female mice were intraperitoneally (i.p.) administered a single dose of chlorpyrifos (40 or 80 mg/kg) at 10:00 h on Day 0 of pregnancy. On Day 3 of gestation, blastocysts were collected and evaluated for gross morphology, micronucleus (MN) frequency, and cell number. A significant increase in MN frequency indicating cytogenetic damage was observed in the treatment groups in comparison to control. The MN frequency revealed a clear dose-dependent increase. There was also a significant decrease in the embryo cell number in the 80 mg/kg treated group. A simultaneous decrease in the cell number and increase in MN frequency may reflect an embryonic developmental disadvantage resulting from maternal treatment with chlorpyrifos.
authors.affiliation: School of Public Health, Shanghai Second Medical University, No. 280 ChongQing Nan Road, 200025 Shanghai, China. tianmiejp@yahoo.com.cn
authors.forename: Y
authors.initials: Y
authors.lastname: Tian
authors.forename: T
authors.initials: T
authors.lastname: Yamauchi
mesh_terms: D000818:Animals; D004390:Chlorpyrifos / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D005865:Gestational Age; D007274:Injections, Intraperitoneal; D007306:Insecticides / Q000008:administration & dosage / Q000633:toxicity*; D018811:Maternal Exposure; D051379:Mice; D008813:Mice, Inbred ICR; D048629:Micronuclei, Chromosome-Defective / Q000187:drug effects; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D011247:Pregnancy
chemical_list: D007306:Insecticides; D009153:Mutagens; D004390:Chlorpyrifos