TY - JOUR T1 - Chronic lung damage by repetitive instillation of gastric fluid in a rat model: Histological and functional changes JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P660 AU - Gisella Borzone AU - Rafael Contreras AU - Andrea Cutiño AU - Fernando Saldias AU - Manuel Meneses Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P660.abstract N2 - Chronic aspiration of gastroesophageal reflux into the lungs has been related to permanent lung damage such as pulmonary fibrosis or bronchiectasis. We developed a rat model of aspiration of gastric content to study lung histological and functional changes.Male Sprague-Dawley rats (300g, n=6/group) received orotracheally: one, two, three or four weekly doses (0.5ml) of a pool of gastric juice (GJ) (pH=1, pepsin concentration 2mg/ml), obtained from a different group of rats. Six rats with no intervention served as controls. Seven days after last instillation, animals were sacrificed and lungs excised in block to study functional and histological changes. End expiratory lung volumen (EELV) was measured by volumen displacement and changes in lung compliance evaluated by changes in k constant of the deflation Pressure-Volume (P-V) curve. Finally, lungs were fixed at 20 cm H2O and histological changes evaluated with H-E stain. One way ANOVA and Spearman correlation were used (p value <0.05 was considered statistically significant).Results: EELV increased progressively from 2.87 ± 0.95 ml in controls to 6.88 ± 1.3 ml in rats after four weekly doses of GJ (p<0.001). The k constant of P-V curve was 0.2206±0.007 in controls and did not change after repeated doses of GJ. Consistent with physiology, a granulomatous interstitial pneumonitis with multinucleated giant cells and prominent bronchiolar involvement were seen in histological studies.Conclusions: Progressive lung hyperinflation characterizes this four-weekly instillation model, largely related to peribronchiolar interstitial inflammation, since no increase in lung compliance was found.Funding: FONDECYT Grant 1120943. ER -