EFFECTS OF ANGIOTENSIN II RECEPTOR ANTAGONISTS IN TREATMENT OF EXPERIMENTAL BULLOUS PULMONARY EMPHYSEMA

Background. Despite numerous studies, the etiopathogenesis of bullous emphysema in lungs of young people has not been finally understood. The article describes the role of transforming growth factor – beta (TGF-β) as an inducer of fibrogenesis and indicator of the degree of development of bullous emphysema. Angiotensin II is also referred to stimulators of fibrogenesis. Aim. The aim of the work was to study in experiment the influence of antagonists of angiotensin-II receptor (Losartan) on remodeling of the bronchial wall and pulmonary tissue in rats with papain-induced bullous emphysema. Materials and Methods. The study was conducted on 70 female Wistar rats randomized into two groups: the control group and the experimental group. Lung emphysema in the animals of the main group was modeled using a modified method of the papain-induced emphysema. Rats with induced emphysema were randomly divided into two subgroups. The 1st group was used as a control model of emphysema. The animals of the second group were introduced the calculated dose of angiotensin-II receptor antagonist (losartan) into the stomach in 12-24 hours after intratracheal instillation of the proteolytic enzyme. A method of paired sera was used. After withdrawal of the animals from the experiment, pneumocardial tissue samples were taken from them for further morphological study. Results.The results of the study revealed a close relationship between angiotensin-II and TGF-β. Angiotensin-II influencing certain mechanisms in fibroblasts, increases the activity of TGF-β. With the underlying elevated level of TGF-β in the lung tissue, the processes of formation of connective tissue were more expressed that probably led to strengthening of interalveolar septa and alveolar walls which may prevent progress of emphysema. Conclusions. In the experiment the influence of preparation from the group of angiotensin II receptor antagonists (losartan) on the processes of remodeling of lung tissue in rats with papain-induced bullous pulmonary emphysema mediated by increase in the activity of the transforming growth factor (TGF beta), was identified. Possibility of use of medical drugs of this group in clinical practice in patients with bullous pulmonary emphysema requires further study.