Products of Sulfide/Selenite Interaction Possess Antioxidant Properties, Scavenge Superoxide-Derived Radicals, React with DNA, and Modulate Blood Pressure and Tension of Isolated Thoracic Aorta

Figure 1

Interaction of ^⋅cPTIO/SeO₃²⁻ with H₂S. (a) Time resolved UV-VIS spectra of the interaction of 100 μmol L^{−1 ⋅}cPTIO with 100 μM SeO₃²⁻ (3 times repeated every 30 s, black) and subsequent addition of 100 μmol L⁻¹ H₂S. Spectra were collected every 30 s for 15 min; the first spectrum, indicated by the solid red line, was measured 15 s after addition of H₂S. Top inset: kinetics of changes in absorbance at 560 nm after addition of 100 μmol L⁻¹ H₂S into ^⋅cPTIO/SeO₃²⁻ (100/100 in μmol L⁻¹) solution at time 0 s. Bottom inset: details of the time resolved spectra of the ^⋅cPTIO/SeO₃²⁻ (100/100 in μmol L^–1) interaction before (black) and after addition of H₂S (100 μmol L⁻¹, the first spectrum is indicated by the solid red line, which is followed each 30 s by: long dash red, medium dash red, short dash red, dotted red, solid blue line, long dash blue, medium dash blue, etc.). (b, c, d, e) H₂S (100 μmol L⁻¹) was added to 100 μmol L⁻¹ solution of ^⋅cPTIO containing different concentrations of SeO₃²⁻ (0-400 μmol L⁻¹, see legend). The kinetics of the reduction of 100 μmol L^{−1 ⋅}cPTIO before and after addition of 100 μmol L⁻¹ H₂S (marked by arrow) was monitored as a decrease of the absorbance at 358 nm minus the absorbance at 420 nm (b, d) and also as a decrease of the absorbance at 560 nm (c, e).

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