Age-related features of tongue arteries remodeling in the experimental animals
Authors: Hnatiuk M. S. , Bodnarchuk I. V. , Tatarchuk L. V. , Hasiuk P. A. 
Published: May 2019

The structural and functional features of the tongue attract the attention of researchers who are often interested in the peculiarities of the structural organization of its arterial bed, which plays an important role in blood supply and morphogenesis of the organ in various injuries. The aim of the research was to study the age-specific features of remodeling of tongue arteries in the experimental animals. The materials of the study were the arterial vessels of the tongue of 30 laboratory albino male rats, which were under normal vivarium conditions. The test animals were divided into two groups. The 1st group consisted of 15 intact, practically healthy animals at the age of 8 months, the 2nd -15 intact rats at the age of 24 months. The euthanasia of experimental animals was carried out by bloodletting under conditions of thiopental-sodium anesthesia. The pieces were cut from the middle part of the tongue and fixed in a 10% neutral solution of formalin. The indicated pieces of tongue were carried out through the ethyl alcohol of increasing concentration and placed in paraffin blocks. After deparaffinization microtome sections 5-7 microns thick were stained with hematoxylin-eosin, by van Gizon, Mallory, Weigert, and toluidine blue. The morphometry of the arteries of the middle (external diameter 51-125 microns) and small calibers (outer diameter – 26-50 microns) of the tongue was carried out. The morphometry of the arteries of the tongue was determined by their external and internal diameters, the thickness of the mediums and adventitia, the height of the endothelial cells, their nuclei, the nuclear-cytoplasmic relations in the endothelial cells, the Kernogan index, and the relative volume of the damaged endothelial cells. Quantitative indicators were processed statistically. The analysis of the obtained morphometric parameters revealed that with the age the arteries of the small caliber have changed more. The outer diameter of arteries of small caliber tongue of the 24-month-old albino rats has increased only for 1.2% and the clearance has decreased by 4.4%. An increase in the outer diameter of the examined vessels and a decrease in their lumen led to a change in the Kernogan index, which with a statistically significant difference (p<0.01) has decreased by 11.8%. The thickness of the mediums of these tongue arteries of the 24-month-old albino rats, has increased by 7.5% and the thickness of the adventitia by 6.2%. During the research in the experimental conditions, the height of the endothelial cells of the examined vessels has decreased by 2.4%, and the diameter of their nuclei – by 3.3%. There was no significant difference between the nuclear-cytoplasmic ratio in the endothelial cells of the studied vessels in the tongue of 8-month and 24-month-old white rats, which indicated a stability of structural cellular homeostasis. The relative amount of damaged endothelial cells in the studied experimental conditions in the arteries of the middle caliber has increased by 17.3%, and of the minor caliber – by 23.7%, which is explained by their age apoptosis. The obtained results testify that with the age there is a structural reorganization (remodeling) of predominantly arteries of the small caliber of the tongue, which is characterized by thickening of their walls, narrowing of the lumen, increasing of the thickness of the mediums and adventitia. The age-related decrease of the Kernogan index of the examined vessels indicates a decrease in their physiological capacity and deterioration of the blood supply of the organ. The morphometric parameters of endothelial cells and their nuclei are altered with the age, maintaining structural cellular homeostasis. The relative amount of damaged endothelial cells in the examined vessels is also increased with the age. Proven, the degree of age-related structural rearrangement of the arterial bed of the tongue depends on the caliber of the vessels.