Clotting of Blood In vivo by Aqueous Homologous Lung Extract,Some Clinical Implications. ∗

Abstract

Pathological studies of the brain in patients dying of pneumonia encephalitis revealed primarily vascular thrombi and hemorrhages. The cerebral lesions were similar regardless of the etiological agent causing the pneumonia, thus suggesting that the cerebral lesions were probably produced by some product of the injured lung tissue.

In an attempt to produce experimentally the lesions of pneumonia encephalitis, rabbit lungs were homogenized with a tissue homogenizer which reduced the tissues to the consistency of a gruel. This homogenized tissue was then diluted 1 to 25 with saline solution and filtered through paper. When this saline extract was injected intravenously into rabbits in amounts of .5 to 1 cc, death ensued in from 30 seconds to 2 minutes. This rabbit lung extract proved to be rapidly fatal to all animals of the species producing nystagmus, ataxia, convulsions, and death. Intravenous injections of similar or larger amounts of extracts of other organs such as brain, liver, kidney, intestine, spleen, and nasal mucosa produced no untoward effect. In order to determine whether or not the toxic action of lung was species specific, rabbits were inoculated intravenously with a 1 to 25 aqueous extract of beef, pork, sheep, guinea pig, and human lung. Of these heterologous lung extracts only the beef lung proved toxic to rabbits, giving a delayed reaction with subsequent death of the animal. Additional proof of the species specificity of the lung extract was demonstrated by intravenous inoculation into guinea pigs and dogs of an aqueous extract of the homologous lung tissue. In each case the inoculated material caused rapid death of the animals. From these experiments it is apparent that lung tissue extract when injected intravenously is fatal to the homologous species.