Histopathological effects of intratracheal administration of artificial lung surfactant in a model of murine paraquat lung *
The pulmonary disorder with paraquat poisoning is called “paraquat lung”．It is an undesiable prognostic sign whose effective regimen has not been developed so far. We hypothesized that the type Ⅱ alveolar cells producing surfactant were damaged by paraquat which was actively accumulated through the blood by alveolar epithelial cells. We made a model of murine paraquat lung to prove this hypothesis. We performed the examination of pulmonary histology：we gave an artificial lung surfactant (surfactenR, Mitsubishi Tanabe Pharma Corporation, Osaka) to one side of the lung using a tracheostomy tube. In the group of paraquat administration, we noticed a lot of red blood cells in alveolar spaces two days later, which was a sign of pulmonary hemorrhage. Then alveolar structures were gradually destroyed, intraalveolar fibrosis became remarkable one month later and fibrosis was confirmed in Masson trichrome stain afterwards. Honeycomb lung was also found two months later. In the group of surfactant administration, the lung parenchyma became thicken and was heavily infiltrated with cellular component. Masson trichrome stain has no fibrous tissues and many alveolar structures remained. Part of the fibrosis decreased clearly in the lung of surfactant administration. (Accepted on October 14, 2010)
