EPR spin trapping of reactive oxygen products of the respiratory burst of phagocytes (use of EPR spectroscopy in biology and medicine. II)

Respiratory burst during phagocytosis of human neutrophils is connected with the production of superoxide anion radical O2.-. This radical changes into further bioreactive oxygen products (especially H2O2 and .OH) which can be harmful to the organism. The principles of EPR spin trapping, the most reliable method for the study of short living free radicals, are presented. Advantages and problems of the study of O2.- and .OH by means of the 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) spin trap were assessed. Overproduction of O2.- (e.g. by chronic inflammation) can be treated with superoxide dismutase (SOD) or other drugs with SOD-like activity. Methods for studying such superoxide scavengers are reviewed. (Fig. 3, Tab. 2, Ref. 88.).