The aim: To study changes in the exocrine and endocrine parts of the pancreas of rats after abolition of monosodium glutamate (MSG) administered in the diet. Materials and methods: White male laboratory rats with a baseline weight of 120 ± 5 g were randomized into 3 groups: 1 – control, 2 – animals with daily feeding of 70 mg/ kg MSG for 8 weeks, 3 – abolition of MSG with transfer of animals to a standard diet and pancreatic examination after 8 weeks. We used histological studies with morphometric analysis and statistical processing of acini and acinar cell areas, Langerhans islets, connective tissue (according to Stolte M.) and adipose tissue. Preparations of pancreas were stained with hematoxylin and eosin and azan. Results: The animals of groups 2 and 3 showed atrophic, degenerative and inflammatory disturbances in the exocrine and endocrine parts of the pancreas, which worsened after 8 weeks of MSG withdrawal (3 rd group). In the preparations, the Langerhans islets were of different shapes and sizes. Small islets predominated, as well as islets with low density of α- and β-cells, different capillary filling with blood and overgrowth of connective tissue in the capillary areas. The acinar cells and acini were reduced, and degenerative abnormalities were detected in the structures. Conclusions: After daily administration of 70 mg/kg MSG for 8 weeks, atrophic and degenerative changes in the exocrine and endocrine parts of the pancreas were revealed. No recovery of pancreatic structures was observed 8 weeks after MSG withdrawal.

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Sodium glutamate, also known as monosodium glutamate (MSG), is frequently used as a flavor enhancer in the food industry. Excessive consumption of sodium glutamate can be harmful to human health. The aim of this study was to investigate the morphological features of the exocrine part of the pancreatic gland under experimental conditions with prolonged exposure to sodium glutamate in the diet. In the experimental study on rats after modeling the action of monosodium glutamate (sodium glutamate) at a dose of 70 mg/kg body weight, the exocrine part of the pancreatic gland was examined using light and electron microscopy after 2, 3, and 5-7 weeks. The experimental study was conducted on white male laboratory rats of reproductive age with an average weight of 168.0±5.0 g. The animals were randomized into two groups: group 1 (n=6) included intact rats and group 2 (n=15) consisted of animals receiving sodium glutamate in their diet. Histological specimens were stained with hematoxylin, eosin, and azan, and electron microscopy samples were stained using the Reynolds method. The results were statistically analyzed using ANOVA analysis with Statistics 20.0.0.2 software. At the early stage of the experiment, changes were observed in the acini with the formation of small clusters comprising 2-3 acinar cells exhibiting increased accumulation of zymogen, which is an early important sign of pancreatitis. Swelling and replacement of the pancreatic gland with connective and adipose tissue progressed over the study period and were accompanied by structural alterations in the pancreatic gland. Round-cell infiltrates appeared in the areas where ducts and vascular bundles were located starting from the 5th week of observation, indicating the development of an inflammatory process. Histopathological changes at the 6th and 7th weeks following prolonged administration of sodium glutamate were similar to the pattern of pancreatitis in humans. Atrophy, degenerative changes, and inflammation were observed in the exocrine part of the pancreatic gland after 6-7 weeks of prolonged oral sodium glutamate intake. Thus, prolonged inclusion of sodium glutamate at a dose of 70 mg/kg body weight in the diet leads to irreversible destructive, degenerative, and inflammatory changes in the pancreatic gland.