Changes in the secretory acinar cells of the rat parotid gland during aging

Abstract

The secretory acinar cells of parotid glands from rats of varying ages have been examined by electron microscopy to determine what age-related changes occur in these cells. The most prominent change noted in these cells is the progressive increase in the amount of lipofuscin granules with age. Lipofuscin granules are membrane-bound structures consisting of lipids, other subcomponents, and a matrix. In addition, these cells contain lipid droplets that are not associated with any other components and tend to accumulate at the base of the cells in older rats. Also, many acinar cells in the glands of old rats contain altered secretory granules which appear to be in the process of degeneration. The accumulation of lipid and degenerating secretory granules appears to be related to the reduced level of cellular secretory activity in the glands of older rats. It is possible that these two types of inclusions contribute to the formation of lipofuscin granules. Lipofuscin and degenerating secretory granules are associated with acid phosphatase, which is demonstrated cytochemically, indicating that these granules are lysosomal structures.

Ultrastructural study of the adult albino rat parotid gland with special reference to the role of stromal telocytes

“…The fact that these lipid droplets were present in adult glands might indicate that their existence was linked to the cellular metabolic activity rather than to aging. These findings are in agreement with those reported by others [20] who observed these structures in the parotid glands of 2-month-old rats. They added that the number of cells containing lipofuscin granules, as well as the number of these granules in each cell, increased in the from the luminal fluid for their return to the circulation.…”

“…All the elements were colored carefully using Adobe Photoshop software using aWacom digital tablet (Wacom Europe GmbH, Krefeld, Germany) to avoid any software mismatches [11]. stroma (Figs 11,12,16,(18)(19)(20). These cells appeared as solitary spindle-shaped cells with euchromatic nuclei and with specific very long and thin moniliform prolongations (telopodes).…”

“…The telocytes with their long telopodes were outside the acinar and ductal basal lamina. Telocytes created a network, especially by branching of their long telopodes that came in contact with the blood and lymphatic capillaries (Figs 11,16,19,and 20). Elements of this telocyte network were interacting with each other (Fig.…”

Structural and functional changes in salivary glands during aging

“…In the submandibular gland of 28-month-old mice, Gresik (1989) observed a reduction in the size of granular convoluted tubule cells, as well as in the occurrence of cells that possessed secretory granules of varying sizes and dense lysosomal bodies. The increase in number of degenerating secretory granules and autophagic vacuoles in parotid acinar cells has been also reported in senescent rats (Kim, 1984).…”

Altered autophagy and sympathetic innervation in salivary glands from high-fat diet mice

“…Moreover the parenchyma of salivary glands are subjected to other influences such as hormones that affect changes in its morphological characteristics leading to local or systemic alterations. 1 One such change is adipose tissue infiltration between acini parenchyma associated with conditions like: Human Imunodeficiency virus (HIV), 2 hypertriglyceridemia, 3 but most commonly with ageing in the absence of any obvious disease process 4,5 .…”