Figure 6.

H₂S is oxidized to sulfite and thiosulfate in culture medium. (A) The levels of H₂S, sulfite (SO₃ ^2‐), and thiosulfate (S₂O₃ ^2‐) after the application of 100 μM Na₂S to the culture medium are shown (n = 6). o/n, overnight incubation. (B) The cytoprotective effect of culture medium 30 min and 2 h after the addition of 100 μM Na₂S on primary cultures of cortical neurons was measured by the WST‐8 assay (n = 6). (C, D) Increase in intracellular cysteine (n = 7) (C) and GSH (n = 6) (D) was measured by HPLC 4 h after the application of medium 30 min and 2 h. *P< 0.05, significantly different as indicated; Tukey−Kramer test. All data shown are means ± SEM.