A PRELIMINARY-STUDY OF THE EFFECT OF GROWTH-HORMONE ON MOUSE PREIMPLANTATION EMBRYO DEVELOPMENT IN-VITRO

The role of growth hormone (GH) in follicular development, ovulation a nd embryo development is currently under reconsideration. In this stud y, we have tried to investigate the effect of GH on preimplantation de velopment. of mouse embryos in vitro. Zygotes and two-cell mouse embry os were cultured without (control) or with GH. For zygotes, the additi on of 0.2 mu g/ml of GH resulted in 77 +/- 1% of blastocysts formed an d 66 +/- 3% rate of hatching (control 64 +/- 4 and 31 +/- 3%, p < 0.05 and p < 0.01, respectively). For two-cell embryos, the addition of 0. 2 mu g/ml of GH resulted in 87 +/- 2% of blastocysts formed and 60 +/- 4% hatching rate (control 76 +/- 4 and 47 +/- 5%, p < 0.05 for both). This positive effect of GH addition implies that the latter can suppo rt mouse preimplantation development in vitro and it suggests, along w ith its local action on the ovary and its possible effects, via the in sulin-like growth factor system, on the tubal and uterine epithelium, a continuous role of this hormone in reproductive physiology from foll icular maturation to embryonic development and, possibly, implantation .