Protective Effect of Dinitrosyl Iron Complexes with Glutathione in Red Blood Cell Lysis Induced by Hypochlorous Acid

Figure 4

The effects of DNIC with glutathione and GSH on the magnitude of free radicals generated in the reaction between HOCl and tert-butyl hydroperoxide (t-BOOH). The EPR spectra were recorded in a reaction medium containing 7.2 mM t-BOOH, 0.75 mM HOCl, and 40 mM DEPMPO (a). The EPR spectra were recorded in the same medium as in (a) in the presence of 0.4 mM GSH (b) or 0.2 mM DNIC (c). The spectra represented a superposition of the EPR signals of spin trap adducts with free radicals (t-BOOH derivatives) including alkoxyl (■) and alkylperoxyl (●) radicals. The EPR spectra were recorded in the same medium as in (a), except that the latter contained 0.4 mM GSH (d) or 0.2 mM DNIC (e), but no t-BOOH. The spectrum (f) was recorded in a medium containing 40 mM DEPMPO, 0.75 mM HOCl, and 0.2 mM FeSO₄, the spectrum (g)—in the same medium but without FeSO₄, the spectrum (h)—in presence of only DEPMPO. The signals of the spin adducts were identified using the data from [45]. (i) The intensity of the signals of DEPMPO spin adducts obtained under conditions corresponding to the spectra (a–c) after 8-minute incubation. Signal intensity of the spin adducts was expressed as from three separate experiments. .

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)