Immunohistological Study of the Major Salivary Glands in the Gray Short-Tailed Opossums (<i>Monodelphis domestica</i>)

Abstract

Marsupials were mammals whose young were born in an undeveloped stage and attached to the mother's nipples, usually in a pouch. Despite, these jaw elements to suckle and digestive system must develop early. Previously we have reported that the morphology of the salivary glands in the gray short-tailed opossums (Monodelphis domestica). This opossum, a kind of marsupial, has three large salivary glands which include the parotid, submandibular and sublingual glands. Parotid glands consist only of serous acinar cells. Submandibular and sublingual glands consist of seromucous secretory end pieces and the submandibular and sublingual glands were mixed glands. This study was purpose to investigate the localization of cytokeratin19 (CK19), aquaporin5 (AQP5) and alpha smooth muscle actin (SMA) in the gray short-tailed opossum parotid, submandibular and sublingual glands. These proteins localization was determined by immunohistochemistry on paraffin sections. Submandibular and sublingual glands showed a broadly similar staining pattern. CK19 was localized to the acinar cells and ductal cells in three major salivary glands. AQP5 was expressed in the luminal only of serous cells. Alpha-SMA was observed around the secretory end pieces. These results are thought to reflect the characteristic of the opossum salivary glands. Further studies are required to unravel obscure matters with cell differentiation and physiological functions of salivary glands among the mammals.