Figure 4.

Kinetics of H₂S consumption and NO generation in the reaction of GSNO with H₂S. (A) Representative recordings by H₂S (black) and NO^• (red) electrodes, illustrating two processes described by eqs 3 and 4. A 400 μM Na₂S solution was prepared in 50 mM potassium phosphate buffer, pH 7.4. When the electrode response reached its maximum, an equimolar amount of GSNO was added, triggering an immediate drop in current at the H₂S electrode and a rise in the NO^• signal. Kinetic traces of NO^• release (B) and H₂S consumption (C) from the reaction mixture containing 250 μM GSNO and 250 μM H₂S at pH 7.4 at 25 °C. Red lines represent a first-order fit for (B) and a second-order fit for (C).