Distribution of pneumococcus-induced augmentation of tissue leukostasis in rabbits: specificity for the pulmonary vascular bed.

We studied whether pneumococcal (PNC) sonicate-induced leukostasis is specific for the lung or whether it occurs in extrapulmonary foci as well. Indium 111-radiolabeled rabbit granulocytes were infused into rabbits that were then challenged with nonviable PNC or normal saline solution. Animals were killed at either 3 or 24 hours after infusion and washed tissue sections from lung, liver, spleen, brain, heart, and kidney were weighed. Tissue 111In radioactivities from each PNC sonicate-challenged animal were compared with those from a control simultaneously injected with saline solution. At both 3 and 24 hours after injection, 111In radioactivity was significantly (p less than 0.01) increased in the lungs of animals challenged with PNC compared with controls injected with saline solution. There were no significant differences between experimental and control animals in liver, spleen, heart, kidney, or brain radioactivities. Animals in another group were injected with PNC through catheters placed in either the right atrium or left ventricle. Significantly (p less than 0.03) increased 111In radioactivity was found after either route of administration only in the lung.