ABSTRACT
We here in determined the histochemical and immunological changes that salivary glands experience as a result of the ageing process. Samples from the inferior lip of children, youngsters and young adults were analyzed by histochemical techniques, Periodic-acid-Schiff, (PAS) Alcian blue (AB) (pHs 1.0 and 2.5) and Toluidine blue for mucosubstances and immunohistochemical staining of S 100 protein and cytokeratin 20, avidin-biotin system (DAB). In children, the techniques used evidenced various reaction degrees in the acinar cells, even within a single acinous. They displayed a slight metachromasia and were alcianophilic at pH 2.5. In youngsters, and especially in adults, glands showed a notable PAS positivity and alcianophilia at both pH levels, and an intense metachromasia. PS 100 was positive in the basal area of the acini and serous demilunes of all groups, the reactivity being higher in adults. Cytokeratin 20 was better observed in ductal cells from children glands. These findings suggest modifications at cytological level and in the chemical composition of the secretory granules, indicating possible functional variations in lip salivary glands related to the ageing process.