Aging of human palatal salivary glands: a histomorphometric study

The aim of the present study was to examine age-related changes in the parenchymal and stromal components of palatal salivary glands of healthy subjects. Palatal salivary gland biopsies were obtained from 120 autopsies and were divided into young, adult, and old age groups. Histomorphometric measurements were performed on hematoxylin and eosin (H&E) stained slides. Parenchymal components included acini and ducts, and stromal components included connective tissue, blood and lymphatic vessels, inflammatory infiltrate, and adipose tissue. The mean volume fraction of each component in each age group was calculated. Statistical analysis was performed by one-way ANOVA and Tamhane tests. The mean volume fraction of the acinar component demonstrated a significant age-related decrease of 48% (P < 0.001). The mean volume fractions of the ducts and of all the stromal components demonstrated a significant age-related increase (P < 0. 001). The inflammatory infiltrate component had the highest increase with aging (1471%), followed by the ducts (177%), blood and lymphatic vessels (138%), adipose tissue (130%), and connective tissue (60%). These age-related changes, the first to be reported in palatal salivary glands from healthy subjects, are different from those described in the labial salivary glands, especially in regard to the significant increase in the parenchymal ductal component, as well as in the stromal inflammatory infiltrate and adipose tissue components. It can be suggested that these changes could have important implications regarding the age-related function of these glands.