Глутамат натрію широко застосовується в харчовій промисловості попри численні повідомлення про імовірний зв’язок між систематичним його споживанням і розвитком деяких захворювань, зокрема атеросклерозу, розладів харчової поведінки, метаболічного синдрому тощо. З огляду на пряму залежність кровопостачання головного мозку від структурної організації і функціонального стану сонного гломуса, особливий інтерес становлять зміни морфології останнього за умов впливу глутамату натрію.

Широке застосування у харчовій промисловості глутамату натрію зумовлює необхідність комплексного підходу до вивчення впливу харчових добавок на тканини органів. Сучасна наукова література містить багато повідомлень щодо розвитку ожиріння, зумовленого споживанням глутамату натрію з продуктами харчування. Проте питання структурних змін стінки судин під впливом різноманітних харчових добавок залишається відкритим. 

The increase in global burden of stroke is hard to overestimate. Every year it continues to be a leading cause of mortality worldwide. Extracranial pathology of the carotid arteries is a major underlying reason of stroke. Given the role of alimentary factors in the development of atherosclerosis of the carotid arteries, possible influence of food additives on the carotid sinus structure is of special interest. Monosodium glutamate is one of the most common food additives that is allowed for consumption in many countries due to it being considered relatively safe. Recent scientific research however points towards the possible adverse effects of monosodium glutamate on the living organism. The aim of this study was to analyze qualitative and quantitative parameters of carotid sinus structural organization of white male albino rats under normal conditions, in the setting of oral monosodium glutamate consumption and after its withdrawal. Carotid sinuses of 30 white male albino rats that had been daily consuming 10 mg/kg of monosodium glutamate for 4 or 8 weeks with subsequent withdrawal for 2 weeks were subjected to qualitative and quantitative analysis at different time-points of the experiment. The data obtained was compared with the results of morphologic and morphometric study of carotid sinuses of 9 rats of the control group. For morphometric analysis, the following parameters were considered: intima thickness, media thickness, adventitia thickness, diameters of the arterioles, venules and capillaries of the carotid sinus vasa vasorum. Summarizing the morphometric analysis results, it is worth noting that, for the duration of 8 weeks of the experiment, steady increase in the thickness of all layers of the vascular wall, but especially intima and adventitia, was observed in the study group. At the same time, the diameter of the arterioles located in the carotid sinus adventitia was decreasing, while venules and capillaries demonstrated invariable increase of their lumen diameter. After 2 weeks of monosodium glutamate withdrawal, the thickness of intima and adventitia continued to increase, while media thickness had somewhat decreased, probably due to fibrosis and dystrophy. The tendency towards narrowing of the arterioles' lumen and widening of the venules and capillaries persisted for at least 2 weeks despite discontinuation of monosodium glutamate. Therefore, systematic consumption of monosodium glutamate may lead to impairment of carotid sinus structural organization, particularly endothelial proliferation, fibrotic and dystrophic changes of media, adventitia thickening as well as microcirculatory vessels damage, that continue to persist despite the food additive withdrawal.

Monosodium glutamate (MG) is a popular food additive that is widely used for flavor enhancement. It is considered relatively safe for consumption in many countries since the time it was first discovered in 1907. However, various disorders have been attributed to MG exposure, while its toxic effects were reported in numerous studies. MG was associated with obesity, metabolic, gastrointestinal, reproductive and other disorders, while damage to satiety center was attributed to its use. However, some of the experimental studies conducted in the past had several flaws in their design or execution that presumably could have affected the results’ extrapolation onto the human population. Further studies are needed to establish monosodium glutamate role in induction and progression of vascular pathology, particularly its effects on the morphology of carotid sinus and adjacent structures, as information on this particular issue is scarce. The objective of this study was to analyze early morphologic changes of carotid sinus under the influence of a low dose of monosodium glutamate administered orally by means of electron microscopy in experimental setting. Carotid sinuses of 10 adult male albino rats were studied by electron microscopy following 4, 6 and 8 weeks of oral administration of 10 mg/kg monosodium glutamate daily. The data was compared with the results of morphologic study of carotid sinus in the control group of 10 adult male albino rats. The data obtained suggests that monosodium glutamate oral consumption is associated with alterations of carotid sinus wall consistent with dystrophy and hypoxia at the early stages of exposure and apoptosis, fibrosis and lipid transformation at the later stages, while carotid glomus shows signs of cellular damage and apoptosis at a slightly later point in time but then the alterations worsen progressively. Further investigation is needed to evaluate morphologic changes of carotid sinus and adjacent structures associated with monosodium glutamate 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