The effect of RU486 on transport, development and implantation of mouse embryos.
Pregnancy was interrupted in Swiss-Rockefeller mice by a single subcutaneous injection of the antiprogesterone RU486 given postcoitally. A dose of 0.1 mg/animal injected on day 1, produced partial inhibition of pregnancy, a notable delay in embryonic development and a slight retention of embryos in the oviducts. When the same dose was injected on day 2, 3 or 4, no implantation sites were seen at autopsy performed on day 12 of pregnancy. Treatment with 0.5 or 1 mg/animal on day 1 produced the loss of a large proportion of the embryos from the genital tract by day 4 of pregnancy and suppressed implantation completely. These observations indicate that preimplantation phenomena in mice are highly dependent on progesterone action.
Roblero
L S
LS
Laboratorio de Endocrinología, Facultad Ciencias Biológicas, P. Universidad Católica de Chile, Santiago.
Fernández
O
O
Croxatto
H B
HB
D000818:Animals; D004305:Dose-Response Relationship, Drug; D010064:Embryo Implantation / Q000187:drug effects; D004622:Embryo, Mammalian / Q000187:drug effects*; D005314:Embryonic and Fetal Development / Q000187:drug effects; D004963:Estrenes / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D015735:Mifepristone; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D011374:Progesterone / Q000502:physiology
D004963:Estrenes; D015735:Mifepristone; D011374:Progesterone