COMPARATIVE MORPHOLOGY OF PRENATAL ANGIOGENESIS OF THE URINARY SYSTEM OF HUMANS AND DOMESTIC PIG (SUS DOMESTICA)
Authors: Tsyhykalo O. , Vladychenko K. 
Published: August 2024

Research has not conclusively clarified the process of angiogenesis in the kidneys that are being formed. Since there are no detailed studies of the microcirculatory bed of the mammalian mesonephros, this is of fundamental interest. The revealed ability to stimulate local angiogenesis and feed from the appropriate vascular bed creates the potential for metanephros transplants, which is important for practical medicine. Therefore, deepening knowledge about the peculiarities of topographical and anatomical transformations of organs and structures of the urinary system of humans and domestic pigs can help in solving the clinical task - the development of kidney xenotransplantation.The aim of the study. The purpose of the work is to determine the peculiarities of the sources of the bookmark and the chronological sequence of topographical and anatomical transformations of the organs and structures of the urinary system of humans and domestic pigs.Material and methods. Specimens of 12 human and 8 domestic pig pre-fetuses were studied. A set of morphological research methods was applied, which included microscopy, three-dimensional reconstruction, morphometry and statistical analysis. Periodization of prenatal development from the standpoint of comparative morphology was carried out according to Carnegie stages.The results. By the stage of CS19 development in the human fetus, four pairs of mesonephric arteries depart from the aorta to the cranial divisions of the primary kidneys. The supply arteriole of the mesonephros is short and ends with a glomerulus. Arteries in the mesonephros of the human fetus show a tendency to dichotomous branching. Human and domestic pig mesonephros contained well-developed glomeruli in the medial parts, which are located relatively close to the aorta. Four well-developed aortic lateral branches supplied the mesonephric glomeruli before CS19 and eight arteries after CS19, while the venous network covered the tubules. Between CS16 and CS18, the mesonephric duct gradually changed its position from dorsolateral to ventrolateral relative to the human mesonephros and even to a ventromedial position in domestic pig embryos (between CS16 and CS19). In human embryos, small branches arising from the caudal cardinal veins that cross the mesonephros appeared at CS15, whereas such branches were already seen in domestic pig embryos at CS11. Subcardinal veins are present along the entire length of the mesonephros in domestic pig embryos, but in human embryos only in the caudal half of the mesonephros. The absence of this network in the cranial part of the human mesonephros at CS15 may be an early marker of future regression of the cranial part of the mesonephros. Cranial regression of the human mesonephros begins at CS15, while that of the domestic pig occurs later at CS19. The use of 3D reconstruction software allowed the assessment of vascular architecture and its relative position to other organs during development without disturbing the spatial arrangement of the embryo.Conclusions. The use of the Carnegie scale to assess the chronological sequence of topographic and anatomical transformations of the organs and structures of the urinary system of humans and domestic pigs makes it possible to conduct an adequate comparison of morphological structures. Reorganization of the arterial blood supply, namely, intercardinal anastomoses to the vessels of the umbilical cord, first appeared in human embryos at CS15, and in domestic pig embryos at CS21. In human and domestic pig embryos, the first appearance of these anastomoses coincided with the beginning of regression of the mesonephros. An early marker of the future regression of the cranial part of the human mesonephros at CS15 may be the regression of the venous network in this area.