The effects of steroid hormones (oestradiol and progesterone) on the appearance of a golden hamster oviduct-specific glycoprotein (GHOGP) in the epithelium of the oviduct of the newborn golden hamster were investigated by immunoblotting and immunohistochemical staining with a GHOGP-specific monoclonal antibody. Newborn golden hamsters (1.5 days old) were injected daily with oestradiol (1 μg) or progesterone (10 μg). An oviductal extract of oestradiol-treated golden hamsters for 4 days apparently immunoreacted with the monoclonal antibody on a broad band with a molecular mass of more than 200 kDa by immunoblotting under reducing conditions. This broad band was consistent with the migration of GHOGP in an extract of adult oviducts. Consecutive daily injections of oestradiol induced the appearance of GHOGP in undifferentiated epithelial cells of the oviduct of neonates. In oviducts of oestradiol-injected animals, GHOGP was first detected in the Golgi region and then increased in amount to fill the supranuclear cytoplasm of the epithelial cells. The inductive effect of oestradiol was dose-dependent. In contrast, consecutive daily injections of progesterone had no effect on the appearance of GHOGP in the oviductal epithelium. The effects of oestradiol and progesterone in organ culture of oviducts were examined in vitro, by culturing oviductal organs from 1.5-day-old newborn golden hamsters in chemically defined medium supplemented with oestradiol or progesterone for 2 days and then subjected to immunohistochemical staining. The immunoreaction was detected only in the epithelial cells of oestradiol-treated oviducts at concentrations of > 0.01 ng ml⁻¹, but not in the cells of untreated and progesterone-treated oviducts. These results indicate that the production of GHOGP in the epithelial cells of the oviduct of newborn golden hamsters is induced by oestradiol both in vivo and in vitro. It is suggested that oestradiol may be involved in the synthesis of GHOGP in the oviduct during postnatal development of golden hamsters.

This study was carried out to determine the effects of growth factors (epidermal growth factor, transforming growth factors-α and -β1, basic fibroblast growth factor, insulin), gonadotrophins (LH, FSH), and fetal bovine serum added to TCM199 medium on cumulus expansion and fertilization during in vitro maturation, and on subsequent embryonic development of bovine cumulus cell-enclosed oocytes. Epidermal growth factor, transforming growth factor-α, LH and FSH enhanced cumulus expansion and oocyte fertilizability. No significant effect was achieved with transforming growth factor-β1 nor with basic fibroblast growth factor. No additive stimulation on cumulus expansion and oocyte fertilizability was observed when epidermal growth factor was combined with LH or FSH. The addition of either epidermal growth factor or transforming growth factor-α to the maturation medium increased the number of fertilized ova that developed to the blastocyst stage. These results demonstrate the potential use of epidermal growth factor and transforming growth factor-α in obtaining high quality mature bovine oocytes for in vitro fertilization.