The origin of red cell fluorescence caused by hydrogen peroxide treatment

Fluorescence in red cells following hydrogen peroxide treatment has been at tributed to lipid peroxidation of the membrane. The putative relationship b etween Lipid peroxidation and fluorescence was questioned by the finding th at BHT and cu-tocopherol, which are thought to inhibit lipid peroxidation, do not inhibit the fluorescence detected by flow cytometry. Furthermore, li pid peroxidation induced in red cells by the Fe(III)-ADP-ascorbate system d id not produce fluorescence. These results require an alternative explanati on for the hydrogen peroxide-induced fluorescence. A role for reduced hemog lobin is indicated by the inhibition of fluorescence by pretreatment of cel ls with CO that binds strongly to ferrohemoglobin and nitrite that oxidizes ferrohemoglobin. Our earlier studies have shown the formation of fluoresce nt heme degradation products during the reaction of purified hemoglobin wit h hydrogen peroxide, which was also inhibited by CO and nitrite pretreatmen t. The fluorescence produced in red cells after the addition of hydrogen pe roxide can, therefore, be attributed to fluorescent heme degradation produc ts. (C) 2000 Elsevier Science Inc.