THE NATURE AND SOURCE OF ESR SIGNAL IN BILIRUBIN

摘要

The ESR signals of bilirubin-IXα were studied including thesamples treated with free radical generating and inhibiting systems,i.e.X-X0.,Fe/EDTA,SOD,mannitol/ascorbate,DTPA,KCN et al.These stable signals allcomprise those originated from a semiquinone radical(g=2.0012)and superoxideradical(g_=2.041,g_=2.0040).The latter is shown to be bound with metal ionsespecially iron,chelated by bilirubin.The iron probably comes from bilirubinprecursor——hemootobin.Active oxygen free radical scavengers may destroy theseradicals.Kinetic curves of regeneration of the bilirubin radicals have beendetermined.Bilirubin is discussed as"active oxygen trap"in mammatians.