Effect of high molecular levan on implantation and embryonic development in mice.

Pregnant Balb C mice were treated daily with levan beginning on either the first or the ninth day of pregnancy. Damage to embryos appeared on the eighth day in mice treated from the first day. In the second group, the damage was apparent two to four days after the levan treatment was begun. In both groups the damaged and dead embryos were found side by side with apparently normal conceptuses. The damage seems to have been caused by lesions to the trophoblast since it only occurred after implantation and placentation, and it appeared to be different from the antitumoral or the graft-rejection delaying effects of levan.