PT  - JOURNAL ARTICLE
AU  - Renato Fraga Righetti
AU  - Samantha Souza Possa
AU  - Viviane Christina Ruiz Schütz
AU  - Homar Toledo Charafeddine
AU  - Fábio Cetinic Habrum
AU  - Carla Máximo Prado
AU  - Edna Aparecida Leick-Maldonado
AU  - Milton Arruda Martins
AU  - Iolanda Fátima Lopes Calvo
TI  - Modulation of oral tolerance on the oxidative stress responses in distal lung parenchyma of guinea pigs with chronic allergic inflammation
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p961
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p961.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p961.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Rationale: We previously had shown that oral induced tolerance contributes to reduce distal lung responsiveness, inflammation and remodelling (Nakashima et al.,2008) in a model of chronic inflammation in guinea pigs (GP). In the present study, we evaluated if these responses were associated to alterations on the oxidative stress responses in distal lung.Methods: GP were submitted to multiple inhalations of ovalbumin (OVA) or normal saline (NS) (2x/wk/4wks). At the same period oral tolerance was induced by offering GP ad libitum 2% ovalbumin in sterile drinking water during 4 weeks (OVA-T1) or starting oral ovalbumin after the 4th inhalation of ovalbumin (OVA-T2). Afterwards, lungs were removed, strips of distal lung were stained for iNOS and PGF2alfa (isoprostane) and analysed by morphometry.Results: In OVA group there was an increase in the iNOS positive cells (20.7±1.0/104μm2) and PGF2alfa content (17.51±2.5%) compared to NS group (p<0.05). There was a decrease in iNOS positive cells in T1 (12.8±1.9/104μm2) and T2 (14.3±2.2/104μm2) compared to OVA (p<0.05). Considering PGF2alfa content, there was a decrease in T1 (6.17±0.4%) and T2 (5.81±0.7%) compared to OVA (p<0.05).Conclusion: Oral tolerance attenuates the oxidative stress responses in distal lung in this animal model of chronic pulmonary inflammation. These results may clarify the mechanisms involved in the attenuation of mechanical responsiveness, inflammation and remodeling of distal lung by oral tolerance, as previously shown in this animal model.Supported by: FAPESP, CNPq, LIM-20-HC-FMUSP.