SALIVARY GLAND CHANGES IN VITAMIN-A-DEFICIENT RATS

Salivary gland pathology was studied in vitamin-A-deficient rats. The principal effects of deficiency were acinar atrophy, proliferation and metaplasia of ductal epithelium, and distension of ducts. Obstruction of excretory ducts frequently occurred when metaplasia resulted in the formation of keratinizing epithelium. Inflammatory changes were related either to degenerative alterations in the ducts or infection of the glands. Marked reduction in the activity of oxidative enzymes was observed during transformation of ductal cells to keratinizing epithelium. Metaplasia was accompanied by pronounced mitotic activity and proliferation of squamous cells into the ductal lumina. Convoluted granular tubules were almost completely lacking in the submaxillary glands. The sublingual glands and the mucous glands of the tongue were not affected as much by the deficiency as were the submaxillary and parotid glands and serous glands of the tongue. © 1969.