Changes in the structural organization of lymph nodes during short-term exposure to monosodium glutamate

Monosodium glutamate is a common food additive that belongs to the group of flavor enhancers used in a wide range of food products. The potentially negative impact of monosodium glutamate on human health prompts us to question the safety of its widespread use. The article presents and analyzes the data of an experimental study conducted on 40 white male and female rats of reproductive age (2.5-3.5 months old) weighing 120-190 g. The purpose of the study is to study histological, morphometric, and ultrastructural changes in the lymph nodes of rats under conditions of short-term exposure to monosodium glutamate. An experimental group of animals (10 male rats, 10 female rats), which was on a standard vivarium diet, was given monosodium glutamate at a dose of 0.07 g/kg of rat body weight by pipette every day at the same time for four weeks, followed by free access to water and food. In animals of the intact group, the structure of mesenteric lymph nodes corresponded to the species norm. In the experimental group of animals, after four weeks of monosodium glutamate exposure, it was found that the paracortical area contained a g larger number of post-capillary venules with a high endothelium compared to the intact and control groups of animals. Changes in the vascular bed were established, in particular, the arteries both in the thickness of the organ and in its hilum contain a thickened wall, their lumen is full of blood. Veins are also full-blooded, dilated and deformed. Swelling of the parenchyma of nodes and signs of immune activity are observed. There is a significant decrease in the relative area of lymphoid nodules and the mantle zone, an increase in the relative area of the medullary substance of the node, corticomedullary index, germinal centers, paracortical area, and medullary cords. Part of lymphocytes of all populations with signs of apoptosis. The other part has an uneven karyolemma contour, the nucleolus is not visualized in all lymphocytes, the cytoplasm is clear and contains organelles. Mitochondria are hypertrophied with a light matrix. Therefore, even a short-term daily exposure to monosodium glutamate, namely four weeks, causes changes in the structural organization of mesenteric lymph nodes.