['To investigate the effects of the recombinant 21-kilodalton N-terminal fragment of recombinant bactericidal and permeability increasing protein (rBPI21) on leukocyte adhesion and the hepatic microcirculation after hemorrhagic shock.', 'Prospective, randomized, blinded, and placebo-controlled experimental study.', 'University research laboratory.', 'Anesthetized Sprague-Dawley rats, weighing 220 to 250 g.', 'Rats were subjected to 60 mins of hemorrhagic shock and subsequent resuscitation to sufficiently restore systemic circulation. The microcirculation of the liver was investigated by intravital fluorescence microscopy 5 hrs after hemorrhagic shock. Four shock groups were compared with a sham-control group. Shock groups received either rBPI21 (10 mg/kg) or placebo either before or after shock period.', 'No differences were observed in hemodynamic, respiratory, or metabolic parameters between the shock groups. However, the hepatic microcirculation showed severe deterioration 5 hrs after shock, indicated by significantly narrowed sinusoids in all shock groups compared with controls (8.5 +/- 0.3 microm vs. 10.0 +/- 0.4 pm). Leukocyte adhesion was markedly increased to comparable values in both placebo groups (619 cells/mm2 and 644 cells/mm2; sham, 168 cells/mm2). Neutralization of endotoxin by administration of rBPI21 before or after shock resulted in plain reduction of pathologic leukocyte-endothelial interaction (138 cells/mm2 and 85 cells/mm2).'] Does recombinant N-terminal fragment of bactericidal/permeability increasing protein ( rBPI21 ) prevent shock-induced microcirculatory alterations in the liver?