The aim of the study was to assess the mechanisms through which leukocyte deactivation occurs upon
hemorrhagic shock. In particular, the influence of beta-
adrenergic tone was evaluated. BALB/c mice were hemorrhaged and resuscitated 60 min after
hemorrhage. Animals were sacrificed 60 min later by
exsanguination. Blood from
exsanguination was cultured ex vivo with
lipopolysaccharide (LPS) and heat-killed Staphylococcus aureus Cowan I (SAC).
Hemorrhage resulted in a major decrease of LPS-induced TNF production whereas
IL-10 production was significantly enhanced. Selective beta(2)-adrenoceptor antagonists (
ICI 118,551) attenuated the decrease in TNF production and further enhanced
IL-10 production.
Hemorrhage did not alter SAC-induced TNF production levels whereas
IL-10 production was increased.
ICI 118,551 further increased the production of both TNF and
IL-10. These data suggest that leukocyte deactivation after LPS stimulation is not a generalized phenomenon since TNF production was maintained when another microbial activator was used.
IL-10 production was enhanced after
hemorrhagic shock, independently of the nature of the triggering agent. Finally, this study demonstrates that beta(2)-adrenoceptor
ligands play an important role in blood leukocyte deactivation to LPS after
hemorrhagic shock.