Microcellular approach to submandibular gland senescence. Myoepithelial markers between aging and tumors

Advance in age outcomes changes that disrupts the function of the salivary glands which are weakened vigorously. Advanced worsening in the histological structure of submandibular gland alters production of saliva. This study was hypothesized to point out the micro-cellular variations with aging in submandibular salivary glands, moreover to detect the role of myoepithelial markers and the propensity of malignant transformation with aging. Fifty male rats were used: group I (young adult), group II (senile). Light microscopic techniques (H&E, Masson trichrome, immunohistochemistry for vimentin, cytokeratin and PCNA) and electron microscopy were used. MDA, GSH and SOD, and a molecular study for p53 was evaluated. The submandibular gland of old rats shows variable sized, shrunken acini, and necrosis. Swollen intercalated ducts with eccentric lumina, and irregular striated ducts are reported. E.M. revealed degenerated myoepithelial cells, cytoplasmic rarefaction, marked reduction of the nuclear chromatin, large macrophages with large lysosomes and many endocytic vesicles. The mean area percent of collagen fibers, vimentin, and cytokeratin in senile rats exposed significant increase and a significant decrease of mean number of PCNA cells when compared to young rats. The mean values of MDA, P53 revealed a significant surge, while that of GSH and SOD exhibited a significant decline when compared to adult rats. Vimentin and cytokeratin have a direct correlation with aging in the submandibular gland. They are concomitant with hyperplastic changes in the gland so they might be a strong indicator of presence of a tumor.