NEUTROPHIL-MEDIATED LUNG LOCALIZATION OF BACTERIA - A MECHANISM FOR PULMONARY INJURY

  • 1 January 1981
    • journal article
    • research article
    • Vol. 90  (3) , 473-481
Abstract
The RES is thought to ensure organ integrity following trauma, burn and sepsis by removing potentially embolic particulate matter and blood-borne bacteria from the circulation. Blockade of the RES with foreign colloids results in a consumptive depletion of opsonic fibronectin, which modulates RES function, and an increase in lung localization of test particles. The role of neutrophils as a contributing factor in the increased localization of blood-borne bacteria was investigated in the [rat] lung after blockade. RES blockade induced by gelatin-coated colloid particle injection resulted in an acute (15 min) increase in the number of 51Cr-labeled neutrophils localized in the lung, with return to control levels at 60 min after blockade. Fibronectin administration following blockade resulted in a significant (P < 0.05) prolonged retention of neutrophils in the lung up to 2 h after blockade. A parallel increase (P < 0.05) in lung localization of heat-killed 14C-labeled Pseudomonas aeruginosa following colloid-induced RES blockade was observed, and fibronectin further increased the number of bacteria localized in the lung. Experimentally induced neutropenia abrogated the effect of colloid injection on lung localization of bacteria. A particulate load results in simultaneous RES blockade and neutrophil margination in the lung, both of which contribute to the increase in lung localization of bacteria. A mechanism for neutrophil-mediated pulmonary injury related to RES dysfunction following trauma is proposed.