CHEMICAL STRESS AND MORPHOFUNCTIONAL CHANGES IN THE RECTUM OF GUINEA PIGS

This study presents the results of an experimental investigation aimed at evaluating the impact of chemical stress on the
morphofunctional condition of the rectum in guinea pigs. A dilute acetic acid solution with moderate mucosal irritation properties
was used as a stressogenic agent. This model reproduces the pathogenetic mechanisms of chemical stress, including localized tissue
damage, activation of inflammatory cascades, and systemic metabolic shifts. Morphological examination of the rectal mucosa after
exposure to the chemical agent revealed signs of irritation and compensatory–adaptive reactions. The epithelial layer exhibited
marked hypersecretion of mucus, reflected in an increased number and size of goblet cells, as well as thickening of the mucous
layer. In certain areas, inflammatory infiltration – mainly consisting of lymphocytes and neutrophils – was observed, indicating
activation of local defense mechanisms. The submucosal layer showed moderate vascular congestion and focal edema, suggesting
impaired vascular permeability.