Abstract
Glands were observed in the reticular groove of all the sheep examined. They were compound tubulo-alveolar and seromucous glands and situated mostly in the submucosa or muscle layer of the left lip of the groove around the reticulo-omasal orifice. Their terminal portion consisted of serous and mucous cells and was surrounded by myoepithelial cells. The serous cells contained large electron-lucent vacuoles with serous granules in the peri- and supranuclear region of the cytoplasm. Myoepithelial cells were observed between the glandular cells and the basement membrane. They extended cell processes over the acinar surface and formed a network by their end-to-end junctions. These glands resembled the esophageal glands with regard to the location in the mucosa and the histological structure. They seemed to appear in juvenile animals with a high frequency. Therefore, it is considered that the area containing these glands may be related to the esophagus in the organogenesis of the forestomach in the sheep.
