Ultrastructural aspects of the nasal glands in the rat.

The secretory granules of the glands in both the lateral nasal wall and the nasal septum of the rat have been studied by electron microscopic techniques. The glandular tissue in the nasal septum consists of one single gland, which histochemically can be divided into a dorsal and a ventral area. The secretory granules in the acinar cells of the ventral area are electron-dense and non-confluent. The dorsal area is composed of acinar cells containing confluent, electron-grey granules and scattered non-confluent, electron-dense ones. The main part of the glandular tissue in the lateral nasal wall is situated around the ostium of the maxillary sinus and can be divided into a dorsal and a ventral part. Ultrastructural studies reveal that the lateral dorsal part resembles the glandular tissue in the ventral area of the septum. Histochemically 2 areas can be distinguished in the ventral part. The acinar cells in one area of the ventral part are characterized by the presence of 2 types of secretory granules: confluent, electron-grey (type A) and non-confluent ones with internal substructures (type B). The other area of the ventral part is composed of acinar cells containing secretory granules resembling those in the dorsal area of the septum.