Effect of ergocornine methanesulphonate on the luteotrophic activity of the ectopic mouse trophoblast

ABSTRACT Virgin mice received 2 blastocysts under the kidney capsule. Following an oestrous cycle which occurred 1–4 days after the operation, nearly all the animals became pseudopregnant. It was found that pseudopregnancy induced by ectopic trophoblast could not be terminated by ergocornine administration. In contrast, this drug was effective in interrupting pseudopregnancy induced by sterile mating. The results confirm previous findings a) that placental luteotrophic hormone starts acting soon after blastocyst implantation and b) that ergocornine exerts no direct effect on the ovary.