REACTION OF PAROTID GLAND MAST CELLS TO CHRONIC ALCOHOL INTOXICATION

Abstract

The goal of this study was to examine the localization and the structural and functional features of mast cells (MC) in the parotid gland in chronic alcohol intoxication. The study was conducted on 15 adult outbred albino male rats receiving 20% ethanol solution as the sole source of drinking for 2 months. The control group included 10 intact animals. Structural changes in parotid salivary glands were studied in paraffin sections, stained with hematoxylin-eosin. MC were demonstrated in cryostat sections stained by Unna’s method; their topography, degranulation were evaluated and their number per field of vision was counted. Serotonin content was assessed quantitatively by using fluorescent microscopy and cytospectrophotometry. In chronic alcohol intoxication, marked variability was demonstrated in the shape of the secretory portions and the size of their glandular cells, which often showed unstained vacuoles. Interlobular ducts are unevenly dilated, their cells had variable height. The number of MC in the connective tissue layer around the interlobular excretory ducts and blood vessels was increased, most of them were in a state of degranulation. However, the content of serotonin in these areas was not changed significantly compared with that in the control group, presumably due to the fact that serotonin released from MC during degranulation, was actively interacting with numerous fibers and terminals of the autonomic nervous system located here, and was quickly trapped by them. Within the lobules, the amount of MC was increased to a lesser extent than in the area of interlobular ducts, but 80% of them were in a state of pronounced degranulation, often with complete disintegration of the cytoplasm. These cells apparently served as the sources of serotonin, the number of which significantly increased in the area of secretory portions. It is suggested that the increased concentrations of serotonin in the area of the secretory portions indicates that under the influence of alcohol intoxication the additional paracrine regulatory mechanisms were activated in the gland, which contributed to its functional activity, aimed at accelerating the excretion of ethanol and its toxic products of metabolism.

Keywords

parotid salivary gland / mast cells / serotonin / alcohol intoxication / rat

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