Ultraweak chemiluminescence: a sensitive assay for oxidative radical reactions

Application of chemiluminescence to the study of lipid peroxidation reactions is based on the occurence of short-lived free radicals and excited states derived from side reactions of the lipid peroxidation process. Thus, the light emission yield is extremely low: 10(-9)-10(15). Chemiluminescence is induced or enhanced by conditions that normally increase lipid peroxidation or that create a peroxidative stress, i.e., toxic effect of hyperbaric oxygen or infusion to the intact organ with organic hydroperoxides. The higher quantum yield of induced-light emission allows a better study of the photoemissive species occurring in the chemiluminescence system; in this regard, spectral analysis is the more accurate method for identifying the chemiluminescence species involved. Since chemiluminescence can monitor continuously the oxidative metabolism of exposed or fiberopatic organs in vivo, it constitutes an adequate tool for the noninvasive study of lipid peroxidation.