UDC 612.014.46:547.466.64:611.133]-08

Monosodium glutamate is one of the most common dietary supplements (E621), approved for use in many countries worldwide, and is considered relatively safe. However, numerous scientific studies have reported various toxiceffects of food additive E621 on organs and tissues, manifested in structural organization and dysfunction changes.The effect of monosodium glutamate, particularly on the structure of blood vessels, requires further study, given the
sometimes contradictory available data in the scientific literature and its prevalent, virtually uncontrolled use. Thisstudy aimed to analyze the morphological changes of the carotid sinus in the early stages of exposure to monosodium glutamate when administered orally in the experiment. The carotid sinus area of 10 laboratory white male rats,which received sodium glutamate orally at a dose of 10 mg/kg/day for four weeks, was studied by morphological
methods at the macro- and microstructural levels. The obtained data are compared with the results of a morphological examination of the same area in 10 animals of the control group. In the early stages, regular consumptionof sodium glutamate may be associated with changes in the structural organization of the carotid sinus, the morphology of the carotid glomus, and the structure of the carotid artery wall, which can lead to cerebral circulatory disorders and functional changes in the carotid glomus. Further study requires the degree of morphological changes with prolonged consumption of monosodium glutamate and features of the structural organization of the sinus in the conditions of its withdrawal.

Carotid artery pathology is one of the leading causes of cerebral stroke. Among thepathogenetic factors in the development of carotid artery damage, disorders of lipidmetabolism, atherosclerosis, and metabolic syndrome occupy a prominent place. The alimentary factor is extremely important in this context. Monosodium glutamate is one of the most common food additives, which is often used uncontrollably and can cause changes in the structure and functions of organs and tissues. The purpose of the study: to analyze the dynamics of morphological changes in the carotid sinus area under the influence of monosodium glutamate when administered orally in an experiment. The area of the carotid sinus of 20 male laboratory white rats that received sodium glutamate orally at a dose of 10 mg/kg/day for 8 weeks was studied by morphological methods at the macro- and microstructural levels after 6 and 8 weeks of the experiment. The obtained data are compared with the results of a morphological study of the same area in 20 animals of the control group. Statistical processing of animal weight was performed using MS Excel 2007 software. Mean ± standard deviation was determined. After 6 weeks of the experiment, when evaluating the histological structure of the wall of the internal carotid artery in the area located directly above the bifurcation, when compared with the control group, multiplication and folding of the intima were found in the experimental group, presumably associated with the proliferation of endothelial cells under the influence of sodium glutamate, detachment of the endothelium and lysis of individual endotheliocytes, as well as uneven thickening of elastic media fibers and disruption of their structure. Attention was drawn to the accumulation of white fat perivasally and in the zone of the carotid glomus, as well as the disorganization of nerves and the expansion of vessels of the microcirculatory channel. After 8 weeks of the experiment, the negative dynamics of structural changes were noticeable: signs of increased inflammatory infiltration, deformation of the vessels of the microcirculatory bed with thickening of their walls and narrowing of the lumen, stasis, noticeable degranulation of cells of type I carotid glomus
cells, the appearance of single labrocytes (mast cells) in the infiltrate. The amount of adipose tissue (white fat) in the area of the carotid sinus and the perivasal bifurcation of the carotid arteries, as well as in the immediate vicinity of the carotid glomus, also increased markedly, and a tendency towards thickening of adipose tissue was noted. Thus, monosodium glutamate with systematic oral use can cause a violation of the structural organization of the carotid sinus, the wall of the carotid arteries and the carotid glomus, and the severity of changes in dynamics increases. Further research is needed to clarify the nature of the structural changes in the carotid sinus under the conditions of withdrawal of monosodium glutamate, as well as to find possible ways of correction

Sodium glutamate (latin – Monosodium glutamate) or monosodium salt of glutamic acid (E621) is one of the most common food additives used to enhance taste sensations and improve the organoleptic properties of food. First isolated in 1907 by Professor Kikunae Ikeda of the Imperial University of Tokyo, monosodium glutamate has been widely used in the food industry due to its ability to enhance the natural taste of food lost during processing and storage. The monosodium salt of glutamic acid, also known as the food additive E621, has been used in most modern food technologies to enhance taste and aroma. The first doubts about the safety of monosodium glutamate as a dietary supplement arose in 1968, after the publication in the British Medical Journal of data that the sodium salt of glutamic acid can cause many diseases [1, 2]. It was then that the term “Chinese restaurant syndrome” was first coined to describe the symptoms of eating glutamate sodium, including severe pain in the stomach, chest, head, flushing, fever, and increased sweating [2, 3]. To date, many studies have been conducted in many countries, but there is no consensus on a safe dose of monosodium glutamate [4, 5]. Studies have shown that excess glutamate can provoke hypertension and stroke, Alzheimer’s disease and nervous system abnormalities, erosive lesions of the gastric mucosa, and weight gain [6, 7, 8]. There are no data on the level of endogenous intoxication of the body with long-term use of monosodium glutamate in significant quantities [9]. However, scientists are particularly interested in the role of systematic use of monosodium glutamate in the  mechanisms of cardiovascular disease, which continue to predominate in the structure of death causes from year to year and, despite significant efforts of the health care system, annually lead loss of capacity for work and disability of a large patient’s number [10]. One of the leading causes of this situation continues to be a stroke, a frequent pathogenetic cause of which is the pathology of the carotid arteries [11, 12]. In current conditions, when many complex factors contribute to the development of atherosclerosis, diabetes, and obesity, scientists are focused on the pathogenesis of vascular lesions, including carotid arteries, their bifurcation zone, carotid sinus, and glomus, under the influence of risk factors. Of particular interest are morphological changes in the wall of the carotid arteries and structures of the carotid sinus in the context of damage and tissue regeneration under the influence of mechanical and chemical factors, to study which often use experimental models [13, 14, 15].