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Ultrastructural immunocytochemical localization of secretory proteins in autophagic vacuoles of parotid acinar cells of starved rats
Author(s) -
Hand A. R.,
Ball W. D.
Publication year - 1988
Publication title -
journal of oral pathology and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 83
eISSN - 1600-0714
pISSN - 0904-2512
DOI - 10.1111/j.1600-0714.1988.tb01537.x
Subject(s) - vacuole , immunogold labelling , secretory protein , immunocytochemistry , autophagy , microbiology and biotechnology , biology , ultrastructure , secretory vesicle , secretion , parotid gland , cytoplasm , biochemistry , endocrinology , exocytosis , pathology , anatomy , medicine , apoptosis
Previous studies have shown that reduction of mastication has marked effects on the structure and biochemistry of the rat parotid gland. Acute starvation results in the formation in the acinar cells of large autophagic vacuoles which contain lysosomal hydrolases and within which secretory granules appear to undergo degradation. In this study we used electron microscopic immunocytochemistry and antibodies to two secretory proteins, oamylase and Brimmunoreactive protein, to determine whether secretory proteins are present in autophagic vacuoles of parotid acinar cells of starved rats. Small vacuoles were observed after 24‐h starvation; they increased in size and number up to 72‐h starvation. Both secretory proteins were present in the secretory granules and in the dense content of the autophagic vacuoles, as shown by immunogold labelling. The lighter matrix of the vacuoles was unlabelled. These findings confirm that secretory granules may fuse with lysosomal structures, where their content of secretory proteins is presumably degraded. Thus, the rat parotid appears to be similar to other secretory cells in which cellular levels of stored secretory proteins may be regulated by the process of crinophagy.