Abstract
The salivary glands produce saliva, which helps keep the mouth and other parts of the digestive system moist. Mammals normally have major and minor salivary glands, and the major salivary glands are composed of three large salivary glands including the parotid, submandibular and sublingual glands. There have been many morphological studies of the submandibular glands of mammals. However, there have been only a few reports on the submandibular glands of opossums. The present study was a histological investigation into the morphology of the submandibular glands in the gray short-tailed opossum. Submandibular glands were obtained from three opossums. All specimens were fixed in 10% neutral formalin solution, and paraffin sections were made by usual methods. They were stained with hematoxylin and eosin, PAS-alcian blue pH 2.5 and mucicarmine.
Macroscopically, the submandibular glands were located at the posterior and inferior portion of the tongue in the anterior neck space. Microscopically, the submandibular glands were composed of many lobules separated by thin fibrous septa. Submandibular glands consisted of serous and mucous acinar cells, showing mixed glands. Serous acinar cells had basophilic cytoplasm and numerous secretory granules and their cytoplasm was partly stained with PAS. Mucous acinar cells had pale-staining cytoplasm stained with alcian blue and/or PAS and mucicarmine. Conclusively, the present study demonstrated characteristic features of the submandibular glands of the gray short-tailed opossum, and it revealed histological data both in accordance with and different from that for the submandibular glands of mammals.
