Ultrastructural changes of rat parotid glands induced by a diet of liquid Metrecal

Summary The ultrastructure of parotid glands was studied in rats fed a diet of liquid Metrecal for two weeks and compared with that of parotid glands of control rats which received a diet of Purina lab chow. The liquid diet induced major alterations of acinar cells, but other parenchymal components were apparently unaffected.Most acinar cells of experimental rats were atrophic and some of these were undergoing necrosis. Lipid droplets and dense bodies (believed to be lysosomes) were numerous in atrophic cells. The Golgi apparatus, quantity of secretory granules, and intercellular canaliculi were smaller than in acinar cells of control rats.Such findings suggest that the secretory process was impaired and support the conclusion that parotid glands of rats maintained on a liquid diet are physiologically less active than those of chow fed rats. The decreased activity, as previously reported, may result from reduced masticatory activity.Supported by U.S.P.H.S. grant DE 02110.