Hydrogen sulfide is an endogenous modulator of leukocyte‐mediated inflammation

Hydrogen sulfide (H2S) is increasingly recognized as an important signaling molecule in the cardiovascular and nervous systems. Recently, H2S donors were reported to induce neutrophil apoptosis and to suppress expression of some leukocyte and endothelial adhesion molecules. Using rats, we examined the possibility that H2S is an endogenous regulator of key inflammatory events at the leukocyte-endothelial interface. Via intravital microscopy, we observed that H2S donors (NaHS and Na2S) inhibited aspirin-induced leukocyte adherence in mesenteric venules (ED50 of 5.0 micromol/kg for Na2S), likely via activation of ATP-sensitive K+ (K(ATP)) channels. Inhibition of endogenous H2S synthesis elicited leukocyte…