Hydroxyl Radical and Its Scavengers in Health and Disease

Figure 1

Effect of iron (ferric chloride) on fibrinogen aggregation, as measured by optical density, and on hydroxyl radical generation expressed as fluorescence intensity according to Manevich et al. (Radiat Res 1997; 148:580-91). A stock solution of 1 mM coumarin-3-carboxylic acid was diluted 1 : 2 with PBS, pH 7.4, and stored at room temperature before the use. Fifty-microliter aliquots of ferric chloride solution at various molar concentrations were added to black plastic microplate wells containing each 100 μL of the coumarin reagent. After 2 min. incubation at RT fluorescence of the hydroxylation product was measured for one second in PerkinElmer 1420 Multilabel Counter at 350/450 nm of excitation/emission wavelength. The results presented in this figure show that the aggregation of fibrinogen is closely related to the extent of hydroxyl radicals generated in the system.