title: Action of lead on early divisions of the mouse embryo.
abstract: The number of cells in mouse embryos 48 h after mating was studied in normal and lead-treated females (0.125, 0.25, 0.5, 1% of lead in the diet). The percentage of embryos in the 4-cell stage compared to those in the 8-cell stage increased after 0.125, 0.25 and 0.5% of dietary lead. After the highest dose an increase in nondivided eggs was also seen which occurred at the expense of 4-cell embryos. The different possibilities, delay of all divisions, delay of only the first division and action of lead on only a part of the embryonic population, are discussed.
mesh_terms: D000818:Animals; D004622:Embryo, Mammalian / Q000187:drug effects*; D005314:Embryonic and Fetal Development; D005260:Female; D007854:Lead / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D013997:Time Factors
chemical_list: D007854:Lead