title: Effects of repeated maternal oral exposure to low levels of trichlorfon on development and cytogenetic toxicity in 3-day mouse embryos.
abstract: Trichlorfon is a widely used broad-spectrum agricultural insecticide. Few studies have evaluated the effects of trichlorfon on developing fetuses, especially at early stages of development after low-level maternal exposures. In this study, we evaluated the direct effects of trichlorfon on preimplantation mouse embryos after 30days of maternal exposure (2, 10 and 50mg/kg/day) via drinking water. On gestation day 3 (dg3), blastocysts were collected and evaluated for changes in gross morphology; cell number; the presence of interphase, metaphase, micronuclei (MN) cells and fragmented and pycnotic nuclei. Embryos in the 50mg/kg/day group had a significantly reduced mean cell number per embryo. Furthermore, there was a significant increase in the frequency of pycnotic nuclei and an absence of metaphase cells in the 50mg/kg/day treated group. None of the developmental endpoints evaluated were observed in the 2 and 10mg/kg/day trichlorfon-treated groups. A simultaneous decrease in the cell number and an increase in the frequencies of absent metaphases and pycnotic nuclei indicate that embryonic developmental deficits observed in the 50mg/kg/day exposure group were associated with cytotoxicity.
authors.affiliation: Shanghai Xinhua Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Children's Environmental Health, 200092 Shanghai, China. tianmiejp@yahoo.com.cn
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.forename: Shufang
authors.initials: S
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.forename: Yijun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Rong
authors.initials: R
authors.lastname: Shi
authors.forename: Wendy
authors.initials: W
authors.lastname: Heiger-Bernays
authors.forename: Yu
authors.initials: Y
authors.lastname: Ding
authors.forename: Pei
authors.initials: P
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Han
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Shen
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects*; D048708:Cell Growth Processes / Q000187:drug effects; D003582:Cytogenetics / Q000379:methods; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D007306:Insecticides / Q000633:toxicity*; D018811:Maternal Exposure / Q000009:adverse effects*; D051379:Mice; D008813:Mice, Inbred ICR; D011247:Pregnancy; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D014236:Trichlorfon / Q000633:toxicity*
chemical_list: D007306:Insecticides; D014236:Trichlorfon