Isolated pulmonary infection acts as a source of systemic tumor necrosis factor

OBJECTIVE: To investigate the local secretion of tumor necrosis factor (TNF) in the lung as a source for systemic TNF. DESIGN: Prospective, randomized experimental trials. SETTING: Laboratory. SUBJECTS: Hartley guinea pigs. INTERVENTIONS: Female guinea pigs were challenged intratracheally with 10(3) to 10(9) Escherichia coli. Two and eight hrs after the bacterial challenge, colony-forming units of bacteria in the lung and blood, TNF and prostaglandin E2 (PGE2) in the bronchoalveolar lavage fluid, and serum TNF concentrations were determined. At the same time, alveolar macrophages were harvested and cultured in vitro, and TNF and PGE2 secretions were measured. MEASUREMENTS AND MAIN RESULTS: TNF and PGE2 concentrations were either not detected in bronchoalveolar lavage fluid or were found in very low levels in control animals. High concentrations of TNF and PGE2, however, were found in bacteria-challenged animals. Two hours after inoculation of bacteria, TNF in the bronchoalveolar lavage...