Parinaric acid as a sensitive fluorescent probe for the determination of lipid peroxidation

The decrease in fluorescence of conjugated polyenic acyl chains is used as a sensitive assay for lipid peroxidation. The fatty acid cis-trans-trans-cis-9,11,13,15-octadecatetraenoic acid (cis-parinaric acid) is introduced into liposomal membranes as free fatty acid or, by using the PC specific transfer protein from bovine liver, as 1-palmitoyl-2-cis-parinaroyl-sn-glycero-3-phosphocholine. The peroxidation process as monitored by the decrease in fluorescence intensity is compared with other peroxidation assay systems. Applications of the new assay system are discussed.