Effect of lipid and propofol on oxidation of haemoglobin by reactive oxygen species.

Abstract

The clinical formulation of the i.v. anaesthetic propofol contains both the substrate for and inhibitor of lipid peroxidation. In these in vitro experiments we have investigated the importance of this potential conflict in a system where haemoglobin was oxidized by reactive oxygen species generated by hypoxanthine and xanthine oxidase. The presence of lipid in the system accelerated the rate of haemoglobin oxidation. Propofol inhibited lipid-induced acceleration but not the underlying rate of reactive oxygen species-induced oxidation. The rate of conjugated diene production, measured semi-quantitatively by ultraviolet absorption at 234 nm, was not reduced by propofol. Propofol may act by preventing haemoglobin oxidation by lipid hydroperoxides.