BOUND IRON ADMIXTURE PREVENTS THE SPONTANEOUS GENERATION OF PEROXIDESIN TOTAL PARENTERAL-NUTRITION SOLUTIONS

Background: Parenteral administration of iron is a matter of controver sy because it is feared that it could contribute to oxidative reaction s. The aim of this study was to verify if irondextran participates in the redox reactions occurring in total parenteral nutrition (TPN) solu tions. Methods: Irondextran was compared with different forms of iron in the interaction with peroxides. Hydroperoxide levels were measured by a colorimetric technique in TPN solutions, in presence of varying s ources (FeCl2, FeSO4, irondextran, iron sorbitol) and concentrations ( 0-0.8 mM) of iron. The consumption and inhibition of peroxide generati on were tested by analyzing the effect of iron on different sources of peroxides (H2O2, tert-butyl and cumen hydroperoxide). The free radica ls produced under conditions of a Fenton-like reaction were measured b y the oxidation of scopoletin. And the proportion of Fe3+ freed by bot h bound-iron sources was counted by measuring the masking effect on th e thiol function of cysteine. Results: Free-iron admixture to parenter al nutrition induces the formation of free radicals, whereas sources o f bound-iron inhibit the generation of peroxides in parenteral nutriti on without implying a Fenton-like reaction. Conclusion: For patients r equiring iron supplementation, bound-iron should be added during the p reparation of TPN solutions, because it protects against the spontaneo us generation of peroxides. (C) 1997 Lippincott-Raven Publishers.