Fig. 6
From: Myocardial Postischemic Injury Is Reduced by PolyADPribose Polymerase-1 Gene Disruption
Electron paramagnetic resonance (EPR) measurement of oxygen radical and nitric oxide (NO) generation from wild type (WT) hearts.
Hearts were perfused with infusion of either the oxygen radical spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) (50 mM) or the NO trap Fe-N-methyl-D-glucamine dithiocarbamate (MGD) (1 mM) and effluent sampled both during the minute prior to ischemia (PI) and during the first minute of postischemic reflow (I/R). In triplicate experiments similar results were seen. Prior to ischemia, no detectable oxygen radical signals were detected. After reperfusion, a prominent 1:2:2:1 quartet of DMPO-OH (hyperfine splitting aN = aH = 14.9 G) was present, demonstrating that superoxide/superoxide-derived hydroxyl radicals were formed. Prior to ischemia, only trace NO(Fe-MGD2) signals were seen, but after reperfusion, a strong characteristic NO triplet signal (g-value 2.04, aN =12.7 G) was present, indicating increased NO formation. Measurements were performed at 9.77 GHz with microwave power of 20 mW or 80-mW and modulation amplitude of 0.5 G or 4.0 G, respectively, for the DMPO or Fe-MGD measurements.