Mechanisms of Ascorbyl Radical Formation in Human Platelet-Rich Plasma
Free radical doublet (a) detected using ESR spectroscopy in (A) PPP, (B) PRP, (C) RBCs, and (D) whole blood. The ESR signal was examined at room temperature, and the following instrument parameters were used in ESR spectroscopy: standard frequency (X-band): 9 GHz; microwave power: 20 mW; modulation frequency: 100 kHz; time constant: 163.84 ms; conversion time: 40.96 ms; receiver gain: ; and the number of data X-scans: 4. The free radical doublet is marked with arrows: “”. Effect of ascorbic acid on the radical formation in human PRP. The intensity of the radical obtained from the reaction of PRP (approximately cells/mL, control) and 30 M, 100 M, 300 M, and 1000 M ascorbic acid in the presence of 100 mM DMPO. ESR analysis was exactly 30 s after the final addition. ESR spectra are labeled to show their components: DMPO- adduct (*). The values of the ESR signal intensity in the bar chart (b) are shown as the means ± SEM (). compared with the control. The instrument parameters were identical to those shown in (a).