title: Heterologous anti-progesterone monoclonal antibody arrests early embryonic development and implantation in the ferret (Mustela putorius).
abstract: Early embryo development and implantation were arrested in ferrets passively immunized with a mouse monoclonal anti-progesterone antibody injected intraperitoneally at 72 and 96 h post coitum (p.c.) or at 72 h p.c. only. In control ferrets injected with mouse serum or 0.9% NaCl, implantation sites were found in all mated females; autopsies were carried out at Day 14 p.c. A total of 34 unimplanted embryos were recovered from the reproductive tract of antibody-treated ferrets and none of these had progressed to the blastocyst stage. When ferrets were treated with antibody at 72 h p.c. and autopsies were carried out at Day 6 p.c., only 1 of 29 embryos recovered had progressed beyond the 4-cell stage in 4 females. In 4 control animals most embryos recovered at Day 6 were at the morula (32%) or blastocyst (28%) stage. Embryos from ferrets treated with antibody were therefore developmentally arrested when recovered 72 h after antibody administration. Plasma progesterone concentrations were approximately 6-fold higher in antibody-treated ferrets with unimplanted embryos (711 +/- 132 nmol/l; 223 ng/ml) compared with control pregnant females (102 +/- 4 nmol/l; 32 ng/ml) at Day 14 p.c. The results are consistent with the hypothesis that the normal course of pregnancy is arrested as a result of antibody binding of progesterone in the circulation, presumably causing a decrease in the amount of progesterone available to target cell receptors, and that heterologous anti-progesterone antibody blocks normal cleavage and embryonic development at an early stage before cavitation.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002335:Carnivora / Q000502:physiology*; D010064:Embryo Implantation / Q000187:drug effects; D004622:Embryo, Mammalian / Q000187:drug effects / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000187:drug effects; D005260:Female; D005289:Ferrets / Q000502:physiology*; D007116:Immunization, Passive; D011247:Pregnancy; D011374:Progesterone / Q000276:immunology / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D011374:Progesterone