EXPRESSION AND LOCALIZATION OF GLUCOSE-TRANSPORTER-1 (GLUT1) IN THE RAT OVIDUCT - A POSSIBLE SUPPLIER OF GLUCOSE TO EMBRYO DURING EARLY EMBRYONIC-DEVELOPMENT

The oviduct fluid mainly derived from the oviduct epithelium is report ed to provide the environment necessary for embryonic development. To elucidate the origin of glucose in the oviduct fluid, we examined the expression and localization of glucose transporter 1 (GLUT1) in the ra t oviduct by Northern blot analysis, immunoblot analysis and immunohis tochemistry using both light and electron microscopy. Northern blot an d immunoblot analyses both showed the presence of the GLUT1 mRNA and p rotein. Specific staining for GLUT1 was observed in the ampulla and th e isthmus, but only slightly in the fimbria and the utero-tubal juncti on, Staining was confined to the luminal surface of the epithelial muc osa. Immunoelectron microscopic analysis revealed that GLUT1 was obser ved only on the surface of the microvilli in non ciliated secretory ce lls, but not in ciliated cells. These findings suggest that GLUT1 play s an important role in the glucose transfer from the oviduct epitheliu m into the lumen and in maintaining the adequate glucose concentration of the oviduct fluid for embryonic development in rat oviduct. (C) 19 95 Academic Press, Inc.