The effect of long-term alcohol intoxication on the morphological structures and enzymatic activity of rat salivary glands

Background: To study changes in the morphological structures and enzymatic activity of the submandibular salivary gland (SMG) and parotid salivary gland (PG) in rats after prolonged alcohol intoxication. Methods: Sexually mature male Wistar rats consumed 20% ethanol (6.9 g/kg/day) for 180 consecutive days. The PG and SMG were collected for morphometric and histochemical analyses (nonparametric Mann-Whitney U test, p < 0.05). Results: After exposure to ethanol for 180 days, the PG showed a change in the shape of the acini and the secretory cells that formed them, uneven expansion of the interlobular excretory ducts, and moderate fatty infiltration in the stroma. After exposure to ethanol for 180 days, the SMG showed fatty infiltration and stromal edema, and changes in acinar cells, intercalated ducts, and striated ducts. There was a significant decrease in the relative and absolute weight of the SMG. The number of mast cells in the PG and SMG and their degranulation index increased 2-fold after exposure to ethanol. All mast cells were highly active. After ethanol exposure, the activity of alkaline phosphatase increased significantly in the myoepithelial cells of the SMG and PG; the activity of NADPH oxidase increased only in the acini SMG, and the activity of succinate dehydrogenase remained at the control level in the acini of both glands. In the ducts of these glands, the activity of other enzymes did not change. Conclusions: Changes in the morphological structures, morphometric parameters, and enzymatic activity of the rat salivary glands after 180 days of ethanol intoxication are shown for the first time. The most pronounced changes were found in the SMG.