Shock-reinfusion injury to the central organs and the effect of free radical scavengers in the rat.

Hemorrhagic shock-reinfusion injury produces critical changes in various organs with the generation of oxidant-free radicals. Some papers have reported that shock-reinfusion injury to the intestine is effectively reduced by the scavengers of free radicals; however, few reports mention the central organ damage caused by systemic hemorrhagic shock-reinfusion injury. Using a rat systemic hemorrhagic shock model, injury to the central organs, being the brain, heart, lungs, liver, and kidneys was assessed by measuring malondialdehyde (MDA). The MDA levels in the lungs, kidneys, and liver were elevated significantly after reinfusion, although there was no elevation of MDA in the brain or heart. These data show that the lungs, liver, and kidneys are easily damaged by shock-reinfusion, but that the brain and heart are relatively resistant. The efficacy of the free radical scavengers, superoxide dismutase plus catalase and allopurinol, were evaluated 30 min after reinfusion. Pathological examination showed that superoxide dismutase plus catalase and allopurinol reduced reinfusion injury in the lungs, liver, and kidneys. Moreover, superoxide dismutase plus catalase reduced MDA levels in both the liver and kidneys, whereas allopurinol reduced MDA levels only in the kidneys after reinfusion. However, these free radical scavengers could not suppress the elevation of MDA in the lungs after reinfusion.