PRIMARY MODULATION BY ESTRADIOL OF THE PRODUCTION OF AN OVIDUCT-SPECIFIC GLYCOPROTEIN BY THE EPITHELIAL-CELLS IN THE OVIDUCT OF NEWBORN GOLDEN-HAMSTERS

The effects of steroid hormones (oestradiol and progesterone) on the a ppearance of a golden hamster oviduct-specific glycoprotein (GHOGP) in the epithelium of the oviduct of the newborn golden hamster were inve stigated by immunoblotting and immunohistochemical staining with a GHO GP-specific monoclonal antibody. Newborn golden hamsters (1.5 days old ) were injected daily with oestradiol (I mu g) or progesterone (10 mu g). An oviductal extract of oestradiol-treated golden hamsters for 4 d ays apparently immunoreacted with the monoclonal antibody on a broad b and with a molecular mass of more than 200 kDa by immunoblotting under reducing conditions. This broad band was consistent with the migratio n of GHOGP in an extract of adult oviducts. Consecutive daily injectio ns of oestradiol induced the appearance of GHOGP in undifferentiated e pithelial cells of the oviduct of neonates. In oviducts of oestradiol- injected animals, GHOGP was first detected in the Golgi region and the n increased in amount to fill the supranuclear cytoplasm of the epithe lial cells. The inductive effect of oestradiol was dose-dependent. In contrast, consecutive daily injections of progesterone had no effect o n 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 gold en hamsters in chemically defined medium supplemented with oestradiol or progesterone for 2 days and then subjected to immunohistochemical s taining. 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 oestradi ol both in vivo and in vitro. It is suggested that oestradiol may be i nvolved in the synthesis of GHOGP in the oviduct during postnatal deve lopment of golden hamsters.