Histochemical localization of salivary glycoproteins in the submandibular gland of aging rats.

It is known that submandibular glands produce serous saliva in the serous demilune cells and mucous saliva in the mucous acinar cells which is a viscous, rich in glycoproteins substance. The aim of this study was the comparative histochemical investigation of acid and neutral salivary glycoproteins in the acinar cells of the submandibular gland in adult and aging rats. Three groups of female Wistar rats were studied: a) young adult rats, 3 months old, b) aged rats 25 months old, c) aged rats 30 months old. Each group included 5 animals. The animals were sacrificed with ether in toxic dose. The submandibular glands were dissected and placed in 10% formaldehyde solution. After fixation they were embedded in paraffin. The paraffin sections were stained with various techniques. We used the: a) Alcian-Blue PH 2,5-Neutral Red b) Periodic-acid/Schiff/Diastase c) Alcian-Blue PH2,5 and Periodic-acid/Schiff/Diastase. We observed that the acinar cells of the aged submandibular glands were filled with acid glycoproteins, while the neutral glycoproteins were localized only in the group of the adult rats. Our results confirm the theory, that lithiasis and chronic inflammations of the submandibular gland, which often happen after the 4th decade of the life, are due to alterations of the mucosubstance composition of the acinar cells.