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-lactobionate organ preservation solution for 48 h and analyzed for evidence of lipid peroxidation. The antioxidant function of the UW solution was evident in stored kidney tissues which had significant reductions in conjugated dienes, lipid peroxides, and Schiff base content compared to fresh controls without vascular flushing. Aerobic incubation of kidney cortex homogenates at 37 degrees C for 60 min resulted in increases in conjugated dienes, lipid peroxides, and Schiff bases in UW-stored kidneys. Schiff base production was markedly higher in UW-stored kidneys during warm incubation than in controls. Addition of Trolox (200 microM) to UW solution resulted in significant reductions in Schiff base production during warm aerobic incubation after preservation. In contrast, adding ascorbate (1 mM) to UW solution potentiated oxidative stress during aerobic incubation, with significant increases in conjugated dienes, lipid peroxides, and Schiff bases which were only partially reversed by further addition of Trolox. Increased oxidative stress was correlated with decreased respiratory function (decreased uncoupled respiration rates and sensitivity to oligomycin inhibition) in aerobically incubated homogenates. This study showed that although the UW solution does have an antioxidant function during hypothermic preservation there remains an increased oxidative stress during warm reoxygenation even in optimally harvested kidneys. The antioxidant effect of the UW solution after preservation can be significantly enhanced using the water-soluble vitamin E analogue Trolox. Antioxidant supplementation of UW solution may be advantageous in preserving kidneys with increased oxidative stresses obtained from suboptimal donors in clinical practice.