Veterinary Research Forum

Abstract The administration of dispersed allogeneic biomaterial (AB) into the para-articular region and joint cavity allows slowing down the processes of tissue destruction in arthritis. The aim of the study was to examine the effect of AB on the course of experimental adjuvant arthritis (AA) in rats. For modeling of AA, complete Freund's adjuvant was injected into the plantar surface of the hind paw of 60 white outbred female rats. The study included intact group, control group, and experimental group. After 37 days of the experiment, blood was collected for hematological analysis and the knee joint with surrounding tissues was harvested for standard histological examination. Intra-articular administration of AB to experimental rats while using complete Freund's adjuvant neutralized the manifestation of signs of a generalized inflammatory process in the joints and reduced the degree of destructive changes in the articular apparatus, preserving the structure of the cartilaginous layer. The use of AB made it possible to stabilize the red and white blood cells levels in the experimental group, as well as significantly increase the reduced level of monocytes. Intra-articular administration of AB during AA modeling exhibits an osteo- and chondro-protective effect, providing positive anti-inflammatory and symptom-modifying effects and weakening the manifestation of pathomorphological changes in the joints of experimental rats.

Abstract To improve the structure of the heart muscle after myocardial infarction, methods of regenerative medicine are used. One of the promising areas is the intra-myocardial administration of acellular allogeneic biomaterial (AB). The AB stimulates the regeneration of organs and tissues. But, the effect of AB on the myocardium after its fibrous ischemic degeneration has not been assessed. The aim of the study was to assess the morphological structure of the heart after cryodestruction in the late period and the use of AB. Chronic myocardial infarction was modeled in 80 male rats. To simulate chronic myocardial infarction and fibrosis formation, contact cryodestruction was performed. After 45 days, during repeated thoracotomy in the main group, AB suspension was injected into the area of the cryogenic myocardial scar. Six injections of 0.50 mg of dry substance were administered. In the control group, physiological solution was injected. After AB administration, following 7, 14, 30, and 45 days, the animals were withdrawn from the experiment, and the hearts were excised for histological and immunohistochemical studies. The AB underwent gradual phagocytosis by macrophages and gradually replaced by loose fibrous connective tissue with the presence of cardiac troponin I⁺ labeled muscle cells, which over time underwent hypertrophy. Cardiomyocytes were grouped in the AB implantation zone as separate clusters. The heart mass did not change in both experimental groups. The use of AB in the area of the formed cryogenic myocardial scar promoted the transformation of dense fibrous connective tissue into loose tissue and its replacement with cardiac muscle tissue.

Abstract An increase in morbidity during times of relatively high functional load on the body such as during pregnancy, confirms the role of metabolic overload in the occurrence of metabolic failures. It is better to take preventive measures such as adjusting metabolic regulation mechanisms in light of the ideal dietary composition. However, this direction is constrained by the lack of information about neurohumoral regulation. The goal of the present study was to learn more about the dynamics of changes in insulin and glucose levels in pregnant cow’s blood. Research on the levels of glucose and insulin in lactating cows demonstrated that ruminants had distinct characteristics in the metabolism of carbohydrates, most notably a lessened reliance of blood glucose on insulin levels. A rise in blood glucose and insulin levels was observed as the gestational stage increased during the third trimester of pregnancy. The intensity of this insulin tolerance was contingent upon the level of productivity and glucose levels during the preceding stages of gestation.

Abstract The aim of the study was to establish the ultrastructural organization features of the gallbladder mucous membrane of an Anglo-Nubian goat. The material for the study was the gallbladder wall’s fragments of an adult Anglo-Nubian goat. Further processing of the obtained samples was carried out according to generally accepted methods. Ultrathin sections were photographed in a Jem-1011 electron microscope at magnifications of 2500-3000. It was found that the gallbladder mucous membrane of an Anglo-Nubian goat is formed by the epithelial layer and its own lamina. The epithelial layer is represented by a single-layer prismatic epithelium, which cells lie on a dense basement membrane. Their nuclei are light, with clear contours. The cytoplasm contains many small mitochondria, vesicles, a small Golgi complex, short cisterns of the granular endoplasmic reticulum, ribosomes, polyribosomes, and rare lysosomes. The apical surface of epithelial cells forms microvilli, and the cytoplasm of the apical pole of cells contains many electron-dense secretory granules. The secret of the latter is excreted into the lumen of the gallbladder, forming a thin layer of glycocalyx on the surface of the epithelium. The lateral surfaces of the cells in their apical part are interconnected by tight contacts. The lamina propria is formed by loose connective tissue containing many blood vessels and nerve fibers.