THE EFFECT OF SIMPLE HYPOTHERMIC PRESERVATION WITH TROLOX AND ASCORBATE ON LIPID-PEROXIDATION IN DOG KIDNEYS

Dog kidneys were preserved by simple hypothermic storage in UW-lactobi onate organ preservation solution for 48 h and analyzed for evidence o f lipid peroxidation. The antioxidant function of the UW solution was evident in stored kidney tissues which had significant reductions in c onjugated dienes, lipid peroxides, and Schiff base content compared to fresh controls without vascular flushing. Aerobic incubation of kidne y cortex homogenates at 37 degrees C for 60 min resulted in increases in conjugated dienes, lipid peroxides, and Schiff bases in UW-stored k idneys. Schiff base production was markedly higher in UW-stored kidney s during warm incubation than in controls. Addition of Trolox (200 mu M) to UW solution resulted in significant reductions in Schiff base pr oduction during warm aerobic incubation after preservation. In contras t, adding ascorbate (1 mM) to UW solution potentiated oxidative stress during aerobic incubation, with significant increases in conjugated d ienes, lipid peroxides, and Schiff bases which were only partially rev ersed by further addition of Trolox. Increased oxidative stress was co rrelated with decreased respiratory function (decreased uncoupled resp iration rates and sensitivity to oligomycin inhibition) in aerobically incubated homogenates. This study showed that although the Uw solutio n does have an antioxidant function during hypothermic preservation th ere remains an increased oxidative stress during warm reoxygenation ev en in optimally harvested kidneys. The antioxidant effect of the UW so lution after preservation can be significantly enhanced using the wate r-soluble vitamin E analogue Trolox. Antioxidant supplementation of UW solution may be advantageous in preserving kidneys with increased oxi dative stresses obtained from suboptimal donors in clinical practice. (C) 1996 Academic Press, Inc.