[Determination of the action of WR 1339 triton on the 1st stages of gestation in the mouse: action of progesterone]

Injection of 600 to 800 mg/kg of Triton W.R. 1339 from day 1 to day 4 of pregnancy is highly noxious in the mouse. Only 12 to 20% of females continue their pregnancy. The causes of this action could be determined. Triton W.R. 1339 has not a direct toxic action on the fertilized ovum, but impairs the hormonal balance of the pregnant mouse, inducing a progesterone deficiency. Daily injection of 5 mg progesterone per animal from day 1-17 or from day 4 to 17 improve pregnancy performance or suppresses completely the noxious action of Triton W.R. 1339.