Bronchoscopy and lung lavage induced bilateral pulmonary neutrophil influx and blood leukocytosis in dogs and monkeys.

Investigators have previously determined that repetitive lung washes attract neutrophils to the lungs. They ascribed this attraction to the release of chemotactic factors. Our studies demonstrate that lavage of one lobe of a lung attracts neutrophhils to unwashed lobes as well; therefore, the attraction of neutrophils cannot be entirely due to the local release of chemotactic agents. Further experiments showed that influx of neutrophils also occurred after bronchoscopy without lung lavage but not after the anesthesia alone. These studies suggest that the lungs have mechanisms that regulate and control neutrophil influx both locally and contralaterally. It is not yet clear whether the controlling mechanisms represent an integrated system in the control of leukocyte traffic through the lungs. In addition, lung lavage and bronchoscopy without lung lavage cause an increase in the blood leukocyte count, with an increase in the number of young neutrophil forms. Lung wash concentrates cause a dramatic increase in the number of blood leukocytes when instilled into a bronchus. These data indicate that lungs contain a material that can stimulate the bone marrow to release leukocytes from its reserves.