The role of leukotriene B4 in endotoxin-induced lung injury in unanesthetized sheep.
In order to examine the role of LTB4, a potent neutrophil chemokinetic and chemotactic factor, in the lung injury induced by Escherichia coli endotoxin, we measured LTB4 in systemic arterial blood plasma and lung lymph in unanesthetized sheep with chronic lung lymph fistulas. E. coli endotoxin (1 microgram/kg) infusion produced a biphasic response. The early period (Phase 1) was a transient pulmonary hypertension. The late period (Phase 2) was a more prolonged period characterized by an increase flow of lung lymph with a high concentration of protein, suggesting increased pulmonary vascular permeability. Peripheral leukocyte counts rapidly decreased during Phase 1 and leukopenia persisted for approximately 5 h. The concentration of LTB4 in arterial plasma and lung lymph significantly increased during Phase 1, and then decreased with a rebound significant increase during Phase 2. That is, LTB4 in plasma and lung lymph showed a biphasic increase after endotoxin infusion. Our data suggest that the elevation of LTB4 is related to the pulmonary leukocyte sequestration in the lung and may contribute to the lung vascular injury induced by endotoxin in unanesthetized sheep.
Fujimoto
K
K
Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.
Kobayashi
T
T
D000818:Animals; D004731:Endotoxins / Q000633:toxicity*; D004926:Escherichia coli; D006439:Hemodynamics / Q000187:drug effects; D007975:Leukotriene B4 / Q000032:analysis / Q000097:blood / Q000502:physiology*; D008171:Lung Diseases / Q000139:chemically induced* / Q000503:physiopathology; D008196:Lymph / Q000032:analysis; D012756:Sheep
D004731:Endotoxins; D007975:Leukotriene B4