Potential biological chemistry of hydrogen sulfide (H2S) with the nitrogen oxides

► Hydrogen sulfide behaves as a nucleophile and a reducing agent. ► Hydrogen sulfide decreases the amount of nitric oxide released by NO donors. ► Hydrogen sulfide alters the normally observed biological response of nitric oxide. ► S-nitrosothiols and nitroxyl probably form from hydrogen sulfide and nitric oxide. ► Hydrogen sulfide reacts with S-nitrosothiols by trans-nitrosation or displacement.