Effects of prostaglandin-f 2α. and a plant protein “trichosanthin”, on 10-day pregnant rabbits

Abstract

The effect of Trichosanthin (TCS), a protein obtained from the roots of Trichosanthis kirilowii, alone or in combination with prostaglandin-F 2α (PGF2α; Troomehamine-sa t on the termination of pregnancy in rabbits was investigated. Intraperitoneal injection of 1 or 2 mg TCS/10-day pregnant rabbits neither altered the serum progesterone (Δ 4P) level nor interrupted pregnancy. Doses of 0.5 or 0.25 mg PGF 2α incorporated in a Silastic-PVP tube and inserted intravaginally, terminated pregnancy within 72 h of treatment in 75 and 16% of the treated does, respectively. By contrast, does treated on day-10 of pregnancy treated does, respectively. By contrast, does treated on day-10 of pregnancy with a combination of a non-effective dose of TCS (1 mg) and a sub-effective dose of PGF 2α (0.25 mg) terminated pregnancy in all the treated animals as no live embryos were found within 3 days of treatment. Pregnancy interruption was associated with a significant reduction of serum Δ 4P and Δ 4PP/20α-dihydro-progesterone (20α-DHP) ratio. The present study indicates that TCS and PGF 2α act synergistically, rendering the termination of 10-day pregnancy possible in the rabbit.It was also noted that pregn ncy cannot be maintained when the serum Δ 4P level drops below 4 ng/ml and n*P/20a-DHP falls lower than 0.6 in the 10-day pregnant rabbit.