Alterations in alveolar macrophage tumor necrosis factor (TNF) response following hemorrhagic shock

The purpose of this study was to determine if hemorrhagic shock alters the alveolar macrophage (MØ) tumor necrosis factor (TNF) response to lipopolysaccharide (LPS) stimulation. New Zealand White rabbits underwent hemorrhage and resuscitation. At 1, 2, 3, 5, and 7 days post-shock, both MØs and peripheral whole blood monocytes were incubated in vitro with saline or Escherichia coli LPS. The supernatants were assayed for TNF activity using the L929 bioassay. Alveolar MØs from hemorrhaged animals showed reduced TNF activity during the first 5 days post-hemorrhage. Maximal depression of TNF activity was observed on days 3 and 5 post-hemorrhage (p < .05). In comparison, peripheral whole blood monocytes showed an increased TNF response on post-shock days 2 and 3. These results suggest that hemorrhagic shock and resuscitation differentially affect TNF response in alveolar and peripheral blood MØ populations.