Induction of mid-term abortion by trichosanthin in laboratory animals.

Trichosanthin, a protein purified from the extract of the root tuber of Trichosanthis Kirilowii, Maxim, given once only induced midterm abortion in the mice and rabbits. The effective I.P. dose for the induction of abortion in 10- or 11-day pregnant mouse was 50 micrograms. In the rabbit a dose and state of pregnancy-dependent response to Trichosanthin-induced abortion was encountered. A dose as low as 0.5 mg Trichosanthin in 22-day pregnant rabbit was adequate but 2.0 mg was needed in 17-day pregnant rabbit. Attempts to terminate pregnancy in the rat and hamster using Trichosanthin was not successful even with higher doses. When compared with prostaglandin-F2 alpha, an established abortifacient, Trichosanthin appeared to be more effective and associated with less side effects in the induction of abortion in the rabbit. Trichosanthin was ineffective to terminate early pregnancy in the 4 species studied.