title: The development of embryos in the uteri of mice treated with actinomycin D before implantation.
abstract: This investigation follows the development of embryos in the uteri of mice in which the differentiation of the implantation chamber has been retarded by the administration of actinomycin D before implantation. For the first 48 h after the induction of implantation both embryonic and extra-embryonic parts of the blastocyst develop, but after 72 h the embryonic parts cease to grow and die. The giant cells and other extra-embryonic tissues, on the other hand, continue to develop for a much longer period, up to 288 h. It is suggested that the actinomycin D, by delaying the formation of the implantation chamber in the endometrium, interferes with the formation of a proper functional connection between the trophoblast and endometrium with the result that the embryo receives insufficient nutrition for its development.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects*; D002454:Cell Differentiation / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology*; D010064:Embryo Implantation / Q000187:drug effects*; D004622:Embryo, Mammalian / Q000187:drug effects; D004717:Endometrium / Q000187:drug effects / Q000502:physiology; D005260:Female; D051379:Mice; D011247:Pregnancy; D013997:Time Factors; D014327:Trophoblasts / Q000187:drug effects / Q000502:physiology; D014599:Uterus / Q000187:drug effects
chemical_list: D003609:Dactinomycin