Hemorrhagic shock and resuscitation cause endotoxemia and hepatocellular damage. Because lipopolysaccharide-binding protein (LBP) enhances cellular responses to endotoxin, our aim was to determine whether LBP contributes to hemorrhage/resuscitation-induced injury by comparing LBP knockout and wild-type mice. Under pentobarbital anaesthesia, wild-type and LBP-deficient mice were hemorrhaged to 30 mmHg for 3 h and then resuscitated with shed blood plus half the volume of lactated Ringer solution. Serum alanine aminotransferase (ALT) necrosis, neutrophil infiltration, and 4-hydroxynonenal by histology/cytochemistry and stress kinase activation by immunoblot analysis were then determined. ALT in wild-type mice was 2,461 ± 383 and 1,418 ± 194 IU/l (means ± SE), respectively, at 2 and 6 h after resuscitation versus sham ALT of 102 ± 6 IU/l. In LBP-deficient mice, ALT was blunted at both time points to 1,108 ± 340 and 619 ± 171 IU/l ( P < 0.05). Liver necrosis after 6 h was also attenuated from 3.5 ± 0.8% in wild-type mice to 1.3 ± 0.5% in LBP-deficient mice ( P < 0.05). After hemorrhage/resuscitation, neutrophil infiltration increased 71% more in wild-type than LBP knockout mice. Similarly, hepatic 4-hydroxynonenal staining, indicative of lipid peroxidation, decreased from 33.8 ± 4.5% in wild-type mice to 11.6 ± 1.9% in knockout mice ( P < 0.05). After hemorrhage/resuscitation, activation of MAPKs, JNK and ERK, occurred in wild-type mice, which was largely blocked in LBP-deficient mice. However, endotoxin in portal blood after resuscitation was not significantly different between wild-type and knockout mice. In conclusion, hemorrhagic shock and resuscitation to mice cause severe, LBP-mediated hepatocellular damage. An absence of LBP blunts hepatocellular injury with decreased neutrophil infiltration, oxidative stress, and c-Jun and ERK activation.
Neutrophil Influx in Response to a Peritoneal Infection withSalmonellaIs Delayed in Lipopolysaccharide-Binding Protein or CD14-Deficient Mice
