FEATURES OF EXTRAORGANIC BLOOD SUPPLY IN THE CONDITIONS CHRONIC STRESS AND IMPROVED PHOTO PERIOD

Abstract

Modern society is experiencing increasing stress, different duration and intensity, due to the lack of stability in the socio-economic sphere of life, its rapid rhythm and pace, significant deterioration of the ecological situation, increasing information load, rest, disruption, disruption due to the increase in the number of people who, by the nature of their professional activities, are forced to work at night. Similar influences in combination with photoperiod disorders have become an integral part of the life of the modern man. All this is the trigger mechanism for the emergence and development of stress reactions. Although stress is an adaptive response of the body, it can provoke the emergence and exacerbation of many pathological conditions. The purpose of our study was to study the morphological features of the extraorganic bloodstream of the epiphysis of laboratory rats under conditions of experimental exposure to chronic stress and impaired photoperiod. The study was conducted on 16 adult male Wistar rats, 10-12 months of age, with a body weight of 240-260 grams. Animals were under standard vivarium conditions but depending on the mode of illumination were divided into 2 groups (8 animals in each group). I group – animals that were in daylight conditions. The illumination intensity was 1000-1500 lux and was carried out by two lamps, which were located on both sides of the cage for 30 days. The second group of animals was in the dark for 30 days. Chronic stress simulation was performed by hyperdynamics. Beginning on day 21 of the experiment, rats were placed in a 10-min water tank for forced swimming. One-time training was carried out for 10 days. It is revealed that the large venous extraorganic vessels look completely bloodless, that is, devoid of the formed elements of blood, only sometimes in their lumen there are single erythrocytes. It is also characteristic that the walls of such vessels are sharply thinned, and in places there are small defects between adjacent endothelial cells. Probably, in this regard, develops a pronounced swelling of the surrounding tissue. It was found that in the arterial system of extraorganic blood vessels of the epiphysis of animals that were under conditions of round the clock illumination also revealed reactive changes. Particularly characteristic of these vessels, from the small to the largest, the complete absence in their lumens of the formed elements of blood. It has been established that blood vessels have the appearance of absolutely light empty spaces. Histological examination of the extra-organ vascular bed of animals under chronic stress and 24-hour darkness revealed that the plasma component prevails in venous vessels occupying a distant position from the organ. It is important to note that this component occasionally occupies almost the entire lumen of a particular segment of the vascular bed. In the presence of blood cells in such blood vessels, the latter are collected in conglomerates, which occupy the peripheral position in the lumen of the blood vessel and closely adjacent to its wall. It is revealed that extraorganic arterial vessels on histological preparations very often look bloodless. Only in some sections, a small number of blood elements are found, concentrated mainly in the parietal zone of the lumen of the blood vessels. According to the results of the conducted morphological study of the state of the extra-vascular bed of the epiphysis of rats under conditions of chronic stress and impaired photoperiod, a decrease in the number of shaped elements of blood and their complete absence in vessels of different caliber and purpose, stratification of blood into shaped elements and plasma, diapedesis. Such morphological features indicate circulatory disorders, the appearance of hypoxia and the development of destructive-dystrophic changes in the tissues of the epiphysis.

Keywords

• pineal gland
• chronic stress
• vascular bed
• hypoxia