STUDY OBJECTIVE: The aim of the study was to determine whether recombinant human extracellular superoxide dismutase type C (rh-EC-SOD C) has antioxidant effects similar to those of the previously studied Cu-Zn superoxide dismutase. DESIGN: Electron paramagnetic resonance spectroscopy was used for quantification of free radical generation during reperfusion of postischaemic isolated rat hearts. The hearts were perfused with Krebs-Henseleit buffer and then subjected to 15 min global ischaemia. N-tert-butyl-alpha-phenylnitrone (PBN) was added as a spin trapping agent to the perfusate. EXPERIMENTAL MATERIAL: 18 hearts from Sprague-Dawley rats (280-400 g) were used. MEASUREMENTS AND MAIN RESULTS: Reperfusion resulted in a burst of radical formation. In presence of rh-EC-SOD C plus catalase, the PBN spin adduct concentration was only 18% (p less than 0.05) of the value in the control group. With bovine Cu-Zn superoxide dismutase plus catalase added to the buffer the corresponding spin adduct formation was 44% of control (NS = v rh-EC-SOD C). CONCLUSIONS: In isolated rat heart, rh-EC-SOD C reduces free radical concentrations at least to the same extent as Cu-Zn superoxide dismutase.
STUDY OBJECTIVE: The aim of the study was to determine whether recombinant human extracellular superoxide dismutase type C (rh-EC-SOD C) has antioxidant effects similar to those of the previously studied Cu-Zn superoxide dismutase. DESIGN: Electron paramagnetic resonance spectroscopy was used for quantification of free radical generation during reperfusion of postischaemic isolated rat hearts. The hearts were perfused with Krebs-Henseleit buffer and then subjected to 15 min global ischaemia. N-tert-butyl-alpha-phenylnitrone (PBN) was added as a spin trapping agent to the perfusate. EXPERIMENTAL MATERIAL: 18 hearts from Sprague-Dawley rats (280-400 g) were used. MEASUREMENTS AND MAIN RESULTS: Reperfusion resulted in a burst of radical formation. In presence of rh-EC-SOD C plus catalase, the PBN spin adduct concentration was only 18% (p less than 0.05) of the value in the control group. With bovineCu-Zn superoxide dismutase plus catalase added to the buffer the corresponding spin adduct formation was 44% of control (NS = v rh-EC-SOD C). CONCLUSIONS: In isolated rat heart, rh-EC-SOD C reduces free radical concentrations at least to the same extent as Cu-Zn superoxide dismutase.