Termination of pregnancy in rabbit and mouse by Trichosanthin.
The effects of a single intraperitoneal injection of Trichosanthin in 6-, 10-, 17- or 22-day pregnant rabbit (2 mg/rabbit) or in 11-day pregnant mouse (50 micrograms/mouse) were studied. Trichosanthin induced abortion in 100% of the 17- or 22-day pregnant rabbits within 48-72 hours and decreased circulating progesterone (delta 4P)concentrations with 24 hrs. On the other hand, the same dose failed to terminate pregnancy in 6- or 10-day pregnant rabbits and caused no significant changes in circulating delta 4P levels. Exogenous delta 4P or prolactin + human chorionic gonadotropin given twice daily failed to reverse the Trichosanthin-induced termination of pregnancy. However, this resulted in a delay of fetal expulsion. It is concluded that Trichosanthin-induced termination of pregnancy is not solely a result of luteolysis but is likely to be due to its toxic effects on placenta, embryo or both. A dose of 50 microgram Trichosanthin given to 11-day pregnant mice resulted in a termination of pregnancy within 96 hours and also a significant decrease in delta 4P levels in 24 hrs. The ratio of delta 4P to 20 alpha-dihydroprogesterone was also decreased steadily after Trichosanthin administration.
D004092:20-alpha-Dihydroprogesterone / Q000097:blood; D000019:Abortifacient Agents; D000020:Abortifacient Agents, Nonsteroidal; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D051379:Mice; D010940:Plant Proteins / Q000494:pharmacology*; D011247:Pregnancy; D011255:Pregnancy Maintenance / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000494:pharmacology; D011817:Rabbits; D013997:Time Factors
D000019:Abortifacient Agents; D000020:Abortifacient Agents, Nonsteroidal; D010940:Plant Proteins; D004092:20-alpha-Dihydroprogesterone; D011374:Progesterone; D011388:Prolactin