A study on pulmonary hemorrhage experimentally produced by the Shwartzman mechanism in rabbits. Possible relationship to pulmonary hemorrhage in man.

The lung was chosen as a target organ of the univisceral Shwartzman reaction in this study. Rabbits were selected as the experimental animal, and E. coli endotoxin was used as the Shwartzman reagent. Preparative procedures were applied through the trachea into the lung in several ways; direct injection of the endotoxin solution and inhalation of the atomized endotoxin solution by natural breathing. The provocation was made by intravenous injection of the same endotoxin 24 hours later. The lung showed severe hemorrhage associated with inflammatory cell infiltration, interstitial fibrosis, macrophage accumulation, etc. The severity and extent of these changes varied, to some extent, between groups as well as between individual animals. The fundamental character was, however, common to all, and the incidence of the lesion in the lung was quite high. The relationship of the present results to idiopathic pulmonary hemorrhage and Goodpasture's syndrome is also discussed from the viewpoint of human pathology.