MORPHOFUNCTIONAL STATE OF MASTICATORY MUSCLES IN THE CONDITIONS OF IODINE DEFICIENCY WITH THE INCLUSION OF GOITRIFEROUS PRODUCTS IN DIFFERENT PERIODS OF ONTOGENESIS

Abstract

The problem of diseases due to the lack of iodine hastop-priority in native and international studies. According to the WHO, more than 1/3 of the Earths population lives in zones of development of iodine deficiency states. According to the UN Childrens Fund (UNICEF), all regions of Ukraine without exception are hidden famine. It is known about the development of myopathy in hypothyroidism, which is often caused by iodine deficiency. Consumption of goitriferous products deepens metabolic disorders. However, skeletal muscles in the conditions of iodine deficiency with the addition of goitriferous products have not been studied. Therefore, the purpose of this study was to determine the peculiarities of the structural organization of the proper chewing and lateral pterygoid muscles of the rats at the stages of postnatal ontogenesis in an experimentally modeled iodine deficiency with the addition of goitriferousproducts. The influence of the iodine deficiency diet in combination with the inclusion of goitriferousproducts on the chewing muscles was studied in male rats of different ontogenetic groups (mature and immature). There were used: injection method for the blood stream study; histological study (hematoxylin and eosin, fuchsinaccording to Hart, trichromic staining according to Mason, to Stidman, hematoxylin-main fuchsin-picric acid according to Van Gieson; histochemical method (succinate dehydrogenase (SDG) according to M. Nachlas method); electron microscopic examination, morphometric analysis (the average value of the lumen of the blood vessels and the thickness of their walls, the number of hemocapillaries in 1 ?m2 of the cross-section of muscular fiber; the number of hemocapillaries that fall on the one muscular fiber; the percentage ratio of oxidation (OMF), oxidation-glycolytic (OGMF) glycolytic (GMF) muscular fibers; the average size of muscular fibers; biochemical methods; statistical analysis. In the injection of the vascular bed with the injectable mass in the masticatory muscles in both mature and immature animals there is the uneven distribution of the injectable mass, a change in the structure of the vascular bed. Histologically, a significant decrease of the arteries diameter and the thickening of their walls, especially in the masticatory muscle itself. The histostructure of the arteries showed the thickening of the inner elastic membrane, the swelling of the nuclei of the endothelial cells. The outer elastic membrane is thickened, irregularly tortuous. There is a decrease of the number of hemocapillaries in 1 ?m2, compared with the norm. The number of hemocapillaries in one muscular fiber decreases. In the study of the venular bed, we determined an increase of the diameter of the venules and veins, in comparison with the norm and the thinning of their walls, both in the proper chewing and in the lateral pterygoid muscles. Ultramicroscopically in the endothelial cells of various ontogenetic groups there is an edema of endothelial cell cytoplasm with marked vacuolation. The perivascular lumen is considerably expanded. At the same time, the more pronounced changes appear in the proper chewing muscle, comparing with the lateral pterygoid one. During the study of histological structure of muscular fibers of masticatory muscles in animals of various ontogenetic groups there is a focal loss of an ordered cross-striation. The growth of the cross-sectional area of all types of muscular fibers is noted. In particular, GMF of the proper chewing muscle actually suffer in immature animals. The layers of the connective tissue are visually expanded, diffuse deposits of glycosaminoglycans are observed. During the study of SDGs activity of muscular fibers, redistribution of different types of muscular fibers can be noted. Both in the proper chewing and lateral pterygoid muscles the number of OGMF has reduced. There was a decrease of the OMFs amount. The number of GMF during this has significantly increased. During morphometric study in experimental animals of both groups the cross-sectional area of all types of muscular fibers, especially GMF, is constantly increasing. In electron microscopic examination, we have determined the significant structural-edematous changes, which are manifested through the violation of the cross-striation of myofibrils, the expansion and blurring of Z-lines. Mitochondria in all types of muscular fibers are enlarged with a matrix of reduced electronic density and collapsed crests. The endoplasmic reticulum is represented by the expanded cisterns and tubules. The Golgi apparatus is expanding; there are vacuoles with light content in it. At the same time, the volume fraction of mitochondria and the volume fraction of myofibrils both in the proper masticatory and in the lateral pterygoid muscles increases. Biochemically, an increase of cholesterol content in the blood of both immature and mature animals (1.68±0.14 mmol/l and 1.46±0.11 mmol/l, respectively) was observed, comparing with the control, which in these groups was 1.65±0.08 mmol/l and 1.37±0.07 mmol/l, respectively. As it is well-known, hypercholesterolemia is an angiogenic damaging factor. Vascular changes trigger stromal-muscular disorders, as it is revealed by us. Significant ioduria is observed in the urine (in the immature rats, 1.40±0.13 ?g/l (p<0.01), in the mature ones 1.88±0.17 ?g/l (p<0.01)