Aging affects morphology but not stimulated secretion of saliva in rats

Background: The role of aging on the salivary gland function still remainscontroversial and inconclusive. This study was undertaken to determinethe effects of aging on the morphology and secretion of salivary glandsusing male Wistar rats.Method: There were three age groups; group A (3 months old; n = 8), group B (6 months old; n = 8), and group C (9 months old; n = 8). Body weights, salivary gland weights, salivary flow rates, pH and salivary levels of sodium, potassium, calcium, chloride, bicarbonate, phosphate and total protein were measured and compared. Hematoxylin-eosin stained histological slides of the salivary glands were assessed for morphological changes.Results: Body weights increased with age while mean parotid gland weightwas significantly higher in group B than in groups A and C. Mean salivary flow rate was significantly higher in group B and C than in group A, andmean salivary pH was significantly higher in group B and C than group A.Analysis of salivary electrolytes and total protein showed that mean levelsof sodium, potassium and bicarbonate increased with age significantly whilemean levels of calcium, chloride, phosphate and total protein did not showsignificant change among the groups.Conclusion: These findings showed that varying changes were observed inthe morphology of salivary glands of aging rats without impaired function.Keywords: Aging, Salivary Glands, Salivary flow rates, Salivary electrolytes, Salivary total protei