[Pathologic characteristics of diffuse alveolar damage induced by paraquat in rat lungs]

Pathologic characteristics and events of paraquat (PQ) induced diffuse alveolar damage were observed by pathohistologic and ultrastructural studies of the lungs of rats, which were given a single intraperitoneal injection of PQ 25mg/kg body weight and sacrificed 6 hours to 45 days later. Results showed that the capillary endothelial and type I epthelial cells were mainly damaged, and associated with interstitial oedema, haemorrhage and hyaline membrane formation of the alveoli, and accentuated alveolitis. The lesions were located in the alveolar structural units and very diffuse in distribution. When the pulmonary damage became irreversible, it then led to fibrosis.