Age‐Related Changes in Rat Sublingual Salivary Gland Morphology¹

Abstract

Sublingual salivary glands were removed from 3.5‐, 12‐, 18‐ and 24‐month‐old Fisher 344 male rats and examined for age‐related changes in morphology. Morphometric analysis revealed stability in the proportional volume of acinar tissue, connective tissue and vascular tissue across age groups. The proportion of gland volume occupied by ducts increased with age due to an increase in proportional volume of striated ducts. A number of qualitative age‐related changes were noted including an increase in squamous metaplasia of duct epithelium, periductal lymphocytic foci and diffuse periductal lymphocytic infiltration. Consolidated deposits were identified in the lumen of intralobular ducts and appeared most frequent in young animals and declined in frequency with age. These morphologic changes while apparently age‐related were evident by 12 months of age indicating that developmental and maturational factors rather than senescence may account for these findings.

Phenotype and cell proliferation activity of duct-like structures in human sublingual glands: a histological and immunohistochemical study

“…Salivary glands exhibit a variety of metaplastic changes 13 and this could explain the cellular phenotypic changes resulting from aging. For Mintz and Mooradian 17 (1987), the sublingual glands underwent squamous metaplasia of the ductal epithelium with age. According to Ihrler, et al 13 (2002), the majority of salivary gland metaplasias develop from basal cells of striated and excretory ducts that have an enormous capacity for pluridirectional morphogenetic differentiation.…”

“…According to Scott 23 (1977), the junction of all age-related microscopic changes may explain the decrease in glandular function. However, despite proof that acini decrease with age, certain studies support that saliva gland functions remain stable in healthy elderly patients 17 , 25 . Sorensen, et al 27 (2014) demonstrated that symptoms of oral dryness (xerostomia) are not associated with age-related degenerative changes in human labial salivary glands.…”

Microanatomical, histochemical and morphometric features of the major and selected minor salivary glands in laboratory Wistar rat

“…Serous acini surface (μm However, the sublingual gland is tightly attached to the mandibular one (Komarek et al, 2000), and are smaller rounded structure situated towards the rostral edge of the mandibular glands, in some circumstances embedded partially in them (Hofstetter et al, 2006). With age, in male rats, the ratio of the excretory ducts versus the acini in the gland increases, and the ductal epithelium undergo frequently squamous metaplasia (Mintz & Mooradian, 1987).…”