Proceedings of the International scientific and practical conference ― Education and Scientific Progress‖ (February 13-15, 2026) / Publisher website: www.naukainfo.com. - Manchester, United Kingdom, 2026. - 206 p.

78 BIOLOGY AND BIOTECHNOLOGY UDC 616.342-002.44-07-085+616.61-002.3-06 Huet Alevtyna PhD, associate professor Kostiuk Oleksandra PhD, associate professor Dvorshchenko Kateryna Doctor of Biological Sciences, senior researcher Taras Shevchenko National University of Kyiv Kyiv, Ukraine QUANTITATIVEANALYSIS OFGASTGENE EXPRESSION INRATGASTRIC MUCOSACELLS UNDER STRESS Abstract. Gastric ulcer is a common disease of the gastrointestinal tract, the mortality rate of which is 5-10% worldwide. The aim of the work was to quantitatively analyze the expression level of the Gast gene (encoding gastrin) in the cells of the gastric mucosa of rats under the influence of experimental immobilization water-immersion stress. Rats were removed from the experiment after 0.5, 1, 2, 3 h of stress exposure and after 12 and 24 h after its withdrawal. Gene expression was studied on isolated total RNA of rats using real-time RT-PCR (RT-qPCR), the results of which were calculated by the relative comparative method (―ΔΔC T Method‖). Catalase activity was determined by the ability of hydrogen peroxide to form a stable colored complex with molybdenum salts. Protein content was determined by Lowry method. Increased expression of the Gast gene, as well as an increase in catalase