Алла Ананіївна Римар, Зоя Михайлівна Небесна, Віолетта Василівна Кульбіцька, Наталія Віталіївна Огінська
Bronchus-associated lymphoid tissue (BALT) is an essential component of the mucosa-associated lym- phoid tissue system and plays a pivotal role in the development of local immune responses in the respiratory tract organs. Under conditions of systemic pathological processes, including experimental carcinogenesis, the structural organization of BALT may undergo significant alterations, reflecting inter-organ immune interactions. The aim of this study was to investigate the histological and morphometric characteristics of pulmonary lymphoid tissue in rats with N,N-dimethylhydrazine-induced neoplastic lesions of the colon. The experiment was conducted on 25 mature white male rats, in which colon adenocarcinoma was induced by sub- cutaneous administration of N,N-dimethylhydrazine hydrochloride for 30 weeks. Histological examination of lung tis- sue was performed using standard light microscopy techniques with picro-Mallory staining. Morphometric parameters were assessed using ImageJ software, and statistical analysis was carried out by one-way analysis of variance (ANOVA). The results demonstrated that at the late stages of the experiment, the lungs of experimental animals exhibited pro- nounced morphological alterations of the lymphoid component, manifested by hyperplasia of peribronchial lymphoid aggregates, polymorphic cellular infiltration, and destructive changes in the bronchial wall. Morphometric analysis revealed a statistically significant increase in the relative proportion of lymphoid tissue in the lungs under DMH-in- duced carcinogenesis compared with the control group (p < 0.001). These findings indicated activation of local immu- noinflammatory responses and structural remodeling of the pulmonary parenchyma in response to a systemic neoplas- tic process. Thus, experimental colon carcinogenesis was accompanied by substantial morphofunctional alterations of bronchus-associated lymphoid tissue in the lungs, reflecting the development of inter-organ immune interactions and systemic immune dysregulation.