Treatment with angiotensin-(1-7) shows a prolonged effect in an experimental model of chronic asthma with the maintenance of the allergen challenge

<bold>Introduction:</bold> Treatment with Ang-(1-7) prevents inflammation and lung remodeling in an experimental model of asthma. <bold>Objective:</bold> To evaluate whether the increase in Ang-(1-7) in the lung can alter lung remodeling and maintain the anti-fibrotic effect after stopping treatment, without stopping the challenge with the allergen. <bold>Methods:</bold> Male BALB/c mice were randomly allocated into three groups: 1) control; 2) sensitized and challenged with ovalbumin (OVA) and 3) OVA treated with Ang-(1-7) [OVA-Ang-(1-7)]. The animals were sensitized with OVA (20µg/ animal, i.p.) on days 0, 14, 28, and 42. On the 21st day, the mice in the sensitized groups began inhalation with OVA (1%, for 30 minutes, 3 times a week) until day 60. From the 35th day, infusion with Ang-(1-7) was started by osmotic mini-pump (1µg/hour, s.c., for 14 days). A portion of the animals in each group were sacrificed on the 49, 54 and 63th day, which corresponds to 0, 7 and 14 days after the end of the infusion with Ang-(1-7). <bold>Results:</bold> OVA group exhibited greater extracellular matrix deposition in the lung compared to the control group. At the end of treatment with Ang-(1-7), no significant reduction in extracellular matrix deposition and alveolar wall thickening was observed. However, 7 and 14 days after stopping the infusion with Ang-(1-7), the mice showed a significant reduction in the deposition of extracellular matrix in the airway wall and alveolar wall thickness, compared to the OVA group. <bold>Conclusion:</bold> Ang-(1-7) prevented inflammation and lung remodeling, attenuated the appearance of pre-fibrotic lesions in the airways of animals with chronic asthma for a long time.