Fig. 3.

H₂S inhibited NO production and iNOS expression in LPS-stimulated macrophages. Primary macrophages were treated with 1 mmol/l l-cysteine, 1 mmol/l PAG, or 200 μmol/l NaHS for 24 h in the absence or presence of LPS (1 μg/ml). NO production (a) and iNOS protein expression (b) were determined as described in “Materials and Methods.” Data were expressed as mean ± SEM for NO production (n = 4) and mean percentage of control ± SEM for iNOS protein expression (n = 3). *P < 0.05; **P < 0.01 compared with vehicle control; #P < 0.05; ##P < 0.01 compared with LPS; †P < 0.05 compared with LPS plus l-Cys. l -Cys l-cysteine