Microscopic and histochemical changes in the liver of adult rats with hyperhomocysteinemia

Abstract

Violation of amino acids metabolism in the human body is the cause of changes in the structure and functions of almost all vital organs and systems. During the last tens of years, significant efforts of scientists have been directed to the in-depth study of such compound as homocysteine (Hcys), which is a thiol-containing amino acid and is produced endogenously during the exchange of methionine and cysteine. Under the conditions of its normal concentration (5-15 μmol/l), it does not pose a threat to the life and health of living organisms. However, in a number of pathological conditions, a pronounced increase of Hcys in blood plasma and inside cells is registered, which leads to the appearance or progression of diseases, including damage of liver tissue. The aim of the research is to study the microscopic and histochemical changes in the liver of adult rats with hyperhomocysteinemia (HHcys). The experiment was conducted on 22 white non-linear adult male rats aged 6-8 months. During the study, the animals were divided into two groups – control and experimental. Chronic resistance to HHcys was modeled by administering thiolactone Hcys in a dose of 200 mg/kg of body weight intragastrically for 60 days to the rats of the experimental group. Histological preparations were studied using a SEO SСAN light microscope and photo-documented using a Vision CCD Camera with a system of image output from histological preparations. Succinate dehydrogenase was detected histochemically according to the Nakhlas method. These studies were carried out on sections made in a cryostat microtome from unfixed tissue using nitro blue tetrazole. To study the specifics of glycogen accumulation in hepatocytes, sections were stained using Schiff’s reagent, after preliminary treatment with iodic acid (PAS reaction) in the Shabadash modification. It was established that the administration of thiolactone Hcys to young rats at a dose of 200 mg/kg led to an increase in the volume of connective tissue elements around the lobules and in the portal tracts of the liver. Thus, it was established that in the liver of adult rats with HHcys, there is a noticeable thickening of the fibrous connective tissue around the lobules and in the portal tracts, trabeculae dissociation, and the appearance of foci of necrosis of the parenchyma of the organ. Hypertrophy and hyperplasia of smooth myocytes in the middle layer and fibrosis of the outer layer of the wall of interlobular arteries, leukocyte infiltration in the portal tracts are observed. A significant decrease in succinate dehydrogenase activity was established histochemically.