The willebrand factor as an indicator of endothelial dysfunction of the thyroid vessels under motor loads

The study of the structural and functional features of the thyroid gland is a subject of interest for both clinicians and representatives of fundamental medical science, which is associated with the prevalence of diseases of this organ. One of the causes of thyroid dysfunction is endothelial dysfunction caused by stress or exercise. Under the influence of muscular activity in the vascular bed of the thyroid gland, the lumen of the vessels expands, the basement membrane swells with dystrophic changes in endothelial cells, circulatory disorders of the type of perivenular and pericapillary hemorrhages, the degree of these changes is associated with the parameters of motor loads. One of the criteria for assessing vascular endothelial dysfunction can be the assessment of the activity of von Willebrand factor. There is no single point of view on the use of the plasma (system) or tissue (local) fraction of the factor to assess the state of the vascular bed. The aim of the study was to assess the state of the vascular bed of the thyroid gland in dogs with various types of motor activity using the immunohistochemical method for determining the intramural fraction of the von Willebrand factor. The objects of measurements were cross sections of different topographic zones of the central part of the right lobe of the organ in 16 control and 67 experimental male dogs, who received single and multiple muscular loads with dynamic control of heart rate. In all analyzed links of the vascular bed, a reaction with antibodies to the factor was detected in the endothelial layer, subendothelial space, and only in a few cases - in the muscular layer of the vessels. It was shown that physical activity influenced the expression of the factor of the vascular wall of the thyroid gland, while single training to a greater extent caused a multidirectional response of the arteries and veins in the center, whereas they by multiple trainings ones were localized in the microvasculature bed mainly in the periphery. When analyzing the results, it was shown that a more informative assessment criterion is not the absolute values of the factor expression, depending on the type of vessels, but the ratio of the square of the immunohistochemical reaction to the area of the vessel wall, reflecting the selective activity of the endothelium and determined by the frequency and duration of loads.