Abstract: Purpose: To study the teratogenic effect of arginine esterase from Agkistrodon halys ussuriensis venom for the clinical application of arginine esterase in the future. Methods: SD rats were divided into five groups: negative control group (normal saline), arginine esterase low dose group (0.06 U / kg), middle dose group (0.18 U / kg), high dose group (0.36 U / kg) and positive control group (vitamine AD). The arginine esterase was given by i.v. continuously for 10 days from the 6th day of pregnancy to the 15th day. Rats were sacrificed one day before birth. The teratogenic effect was determined by evaluating and comparing general criteria (including locomotor activity, growth rate, appetite and death rate), cyesis criteria (including implantation number, died fetus number, living fetus number, resorption embryo number, fetus body weight, fetus body length, fetus tail length and fetus sex ratio), and teratosis criteria (including external appearance teratosis rate, internal organ teratosis rate and skeleton teratosis rate). Results: The body weight of the female rats and the fetuses decreased at the dosage of 0.36 U / kg compared with the negative control animals (P<0.05). But there were no significant differences in teratosis rates(P>0.05). This result showed that arginine esterase had toxic effect on fetus but had no teratogenic effect even at high dosage. There were no significant differences in other criteria between the lower dose arginine esterase treated animals and the negative controls(P>0.05). Conclosion: The safe dosage of arginine esterase for rats in teratogenic effect is 0.18 U / kg and it has toxic effect to embryo at higher dosage. The dosage of 0.18 U / kg is equivalent to 15 times of the clinical dosage of "Qingshuanmei" whose main component is arginine esterase, and it indicated that clinical usage of the arginine esterase is safe.

Key words: snake venom, arginine esterase, teratogencity test