Гістологічна характеристика стану скелетних м’язів щурів на тлі моделювання нестачі мелатоніну в комбінації з різними видами стресових навантажень

Abstract

В статті розглядаються гістологічні зміни в будові скелетних м’язів (на прикладі чотирьохголового м’язу стегна) на тлі моделювання умов нестачі мелатоніну в комбінації з різними видами стресових навантажень (іммобілізаційний стрес, надмірні фізичні навантаження).

В статье рассматриваются гистологические изменения в строении скелетных мышц (на примере четырёхглавой мышцы бедра) на фоне моделирования условий недостатка мелатонина в комбинации с различными видами стрессовых нагрузок (иммобилизационный стресс, чрезмерные физические нагрузки).

Excessive physical activity and immobilization is a stressful factors that can cause functional changes in different levels of the body. Such changes in motor activity, as well as violations of the photoperiod stimulate the processes of lipid peroxidation, contribute to the accumulation of free radicals that cause damage to the structure of cell membranes. Melatonin is able to reduce the aggressive effects of the above stress factors in the structures of the Central nervous system. At the same time, the data highlighting the condition of the skeletal muscles at the microscopic level by action of the mentioned factors in the literature was not found. Therefore, the issue of morphological changes of skeletal muscles after exposure to immobilization stress and excessive physical activity in combination with a violation of the photoperiod is important. Microscopy of histological preparations obtained from control group 1 revealed a moderate vacuum between the fiber and the intervals between the beam due to development of connective tissue. Such changes may indicate a decrease in the number of vessels of the micro circulatory bed, which can cause violation of blood flow in tissue. This can lead to swelling of the tissue studied. For violations of the micro circulation in the tissue there are changes in the structure of muscle bundles, which manifests as damage to the integrity of a set of myofibrils. Prolonged swelling of the tissue can lead to the development of atrophy in the investigated structures. Also in studies of histological preparations of this group of animals in some cases in thick tissue, the appearance of adipocytes (from immature forms to decorated layers of fat). These changes can also be a symptom of atrophic changes in the structure of muscle tissue. In the study of histological preparations animals of the experimental group No. 1 revealed a clear breakdown of fibrillar complex muscle bundles. The spaces between the fibers is increased and pronounced, revealed the growth of connective tissue between the fiber and between the beam intervals. Muscle fiber looks damaged and becomes “mosaic”. Identified histological changes in animals of this group are similar to the changes in the control group No. 1. So, having considered the above changes, it should be noted that damage to structures of the myofibrils leads not only the state of chronic homestones, and a state of immobilization stress on the background of modeling a lack of melatonin. Microscopy of histological preparations received from the experimental group № 2 it has been discovered that muscle fibers do not take dyes. The emergence of such changes may indicate the effects of tissue hypoxia caused by as muscle strain, which were experimental animals. The space between the fibers somewhat increased muscle bundles appear optically homogeneous. There was also an increase between the beam spacing and the proliferation of connective tissue. It should be noted that the increase in gaps between the muscle fibers and proliferation of connective tissue was also observed in animals of the control group No. 1. After analyzing the histological changes in the structure of the investigated tissues, it should be noted that the condition of chronic home alone in combination with various types of stress loads can lead to disruption of the microcirculation, damage to the integrity of a set of myofibrils, which will eventually lead to atrophic changes in the tissue.