Nitric acid-induced injury in the hamster lung

Severe airway lesions can result following exposure to various pathogens or toxic gases and can show a variety of pathologic lesions including necrotizing bronchitis, bronchiolitis and bronchiectasis. The purpose of this study was to develop a chronic airway lesion in the hamster, a species recognized for its lack of endogenous pulmonary disease. We have successfully adapted a technique of inducing rabbit airway lesions with nitric acid to the hamster lung and have characterized the morphologic, morphometric and biochemical features of the model. Following a transorotracheal instillation of 0.5% HNO3 in saline, Syrian golden hamsters showed during a 60-day study period a spectrum of airway changes including acute bronchitis, acute bronchiolitis, obliterative bronchiolitis, bronchiolectasia and bronchiectasis. Morphometric changes in the HNO3-treated hamsters included decreased lung volumes and decreased internal surface areas. Biochemical changes showed increases in lung weight and in total collagen and elastin. The model is useful because a prolonged insult to the airways develops rapidly and persists over a long period of time, important features for investigations designed to study the effects of superimposed insults upon pre-existent airway lesions.