RESUMO
BACKGROUND AND OBJECTIVES: The vomeronasal organ of the rat is a chemosensory organ located at the nasal septum. The distribution of nitroxidergic nerve fiber in olfactory system such as olfactory bulb, accessory olfactory bulb and olfactory epithelium was well documented, but vomeronasal organ which is a component of olfactory system and the receptor structure of the accessory olfactory system was rarely reported and discorded. The aim of this study was to determine the distribution and role of nitirc oxide (NO) in the rat vomeronasal organ using NADPH-diaphorase histochemistry. MATERIALS AND METHODS: Histochemical staining for NADPH-diaphorase in the rat vomeronasal organ was done. RESULTS: The NADPH-diaphorase positive reaction was observed in the blood vessels, nerve fibers around vessels and submucosal glands of vomeronasal organ. However, receptor area which is generally called the neuroepithelium and receptor free area were not seen. CONCLUSION: These results suggest that NADPH-diaphorase positive reaction shows tissue specific expression in the rat vomeronasal organ.