BN52021 stabilizes the oxidant-antioxidant equilibrium in peritoneal lavage fluid in experimental hemorrhagic shock.

The overproduction of highly reactive oxygen metabolites initiates and contributes to the damage to abdominal organs in hemorrhagic shock (HS). Peritoneal environment including free cells located in peritoneal cavity may interact with the inflammatory processes occurring in abdominal organs during HS. Peritoneal lavage was carried out in 48 rats divided into following groups: (1) control, (2) untreated HS for 75 minutes, (3) HS + restoration of blood volume with polyelectrolyte solution (PES) 60 minutes after blood withdrawal, and (4) HS + platelet activating factor (PAF) receptor antagonist BN52021 directly after bleeding + PES after 60 minutes of HS. Peritoneal lavage fluid (PLF) was examined for Cu-, Zn-superoxide dismutase (SOD) activity, sulfhydryl compound (-SH) concentration, and malondialdehyde (MDA) level measured as thiobarbituric acid reactive substances (TBARS). The untreated shock (group 2) as well as HS + PES (group 3), resulted in significant increase in cell numbers in PLF. In groups 2 and 3, the SOD activities were not detected while -SH group levels were significantly higher, than those in the control. The group of shocked rats after blood volume restoration with PES was the only group where the MDA in PLF was found. The highest -SH group concentrations and detectable SOD activities were recorded in shocked rats treated with BN52021 and PES. Systemic hemorrhage may cause significant alterations in the oxidant-antioxidant (O-A) balance in peritoneal cavity, accompanied by significant elevation of number of cells lavaged from peritoneal cavity. There is an escalation of disturbances in O-A balance in peritoneal lavage fluid due to restoration of blood volume. BN52021 may exert beneficial effects stabilizing peritoneal antioxidant system in the hemorrhagic shock.