The effects of heparin-binding epidermal growth factor-like growth factor on preimplantation-embryo development and implantation in the rat

This study examined the effects of heparin-binding epidermal growth factor- like growth factor (HB-EGF) on preimplantation-embryo development and initi ation of implantation in the rat. In vitro studies showed that HB-EGF impro ved the development of 8-cell embryos to the blastocyst stage in a concentr ation-dependent manner, and the growth factor had no effect on the cell num ber of the blastocyst developed. Intraluminal injection of an anti-HB-EGF a ntiserum into the uterine horns at 0600 h on day 5 of pregnancy decreased t he number of implantation sites (blue dye reaction) at 0200 h on day 6. Int raluminal injection of 20 mu l of HB-EGF solution (10 or 100 ng/ml) into ea ch uterine horn induced implantation in about half of the ovariectomized pr ogesterone-treated delayed implanting rats, and the number of implantation sites per rat increased dose-dependently. These results suggest that HB-EGF is involved in the preimplantation-embryo development and initiation of im plantation in the rat.