Reduction of anxious and aversive behavior to allergen in mice with allergic lung inflammation and treated with angiotensin-(1-7).

<bold>Background:</bold> Mechanisms of allergic lung inflammation are well widely studied but little is known about its influences on brain activity, and behavior. The Angiotensin-(1-7) [Ang-(1-7)] / Mas receptor axis is associated with attenuation of airway inflammation, pulmonary remodeling and bronchial hyperresponsiveness in an experimental model of asthma. <bold>Aims:</bold> In this study, we assessed a possible change in the behavior induced by allergic lung inflammation. Furthermore, we asked if the treatment with Ang-(1-7) could reverse this behavior change. <bold>Methods:</bold> Mice were assigned to three groups: Control, OVA and OVA+Ang-(1-7). In the OVA groups, mice were sensitized to ovalbumin (OVA; 20 μg, i.p., four times, 14 days apart) and challenged three times per week (1% by nebulized, days 21-46). After 35 days, mice were treated with Ang-(1-7) (days 35-48). An adapted classic passive avoidance test was performed, using an OVA aerosol as an aversive stimulus, in addition, to the Elevated Plus Maze (EPM) test. <bold>Results:</bold> Allergic mice avoided entering the aversive compartment of the apparatus that had been previously associated with nebulization of the allergen. At the same time, the control, and OVA+Ang-(1-7) groups still moved into the aversive side of the test box. Furthermore, OVA+Ang-(1-7) group showed an increase in the percentage of time and entries in the open arms of the EPM. The treatment with Ang-(1-7) attenuated pulmonary remodeling and decreased IgE levels. <bold>Conclusion:</bold> The activation of Ang-(1-7)/Mas receptor signaling could be further investigated as an additional strategy for treating asthma-related anxiety.