This study was aimed to determine whether administration of an inhibitor of caspase-3 protects hepatocellular function in rats with hemorrhagic shock and whether caspases are important pharmacological targets in attenuating liver injury induced by hemorrhagic shock and resuscitation. Male adult rats were subjected to hemorrhagic shock by bleeding to a mean arterial blood pressure of 35-40 mmHg for 1 h and were then resuscitation with 60% shed blood and lactated Ringers solution. A subgroup of animals was injected i.v. with 2 mg/kg caspase inhibitor, Z-DEVD-FMK, prior to blood withdrawal. Fas ligand expression was markedly elevated and caspase-3 activity increased by 3-fold in hemorrhagic untreated rats. The increase in caspase-3 activity was prevented by administration of Z-DEVD-FMK prior to shock and resuscitation. Poly (adenosine diphosphate ribose) polymerase proteolysis was reduced in rats treated with the caspase-3 inhibitor compared with hemorrhagic untreated animals. Plasma aspartate aminotransferase and alanine aminotransferase values showed a significant increase at 6 h of shock in untreated animals (+360% and +515% as compared with sham-operated animals, respectively). Administration of the caspase-3 inhibitor did not prevent the increase in plasma transaminases. The cytosolic concentration of thiobarbituric acid-reactive substances (TBARS) and the oxidized:reduced glutathione ratio increased in the animals with hemorrhagic shock (+94% and +170%, respectively). These parameters were not significantly modified by pretreatment with Z-DEVD-FMK. It appears that caspase inhibition does not attenuate hepatocellular depression and liver injury induced by hemorrhagic shock and resuscitation.