Fig 3.

Induction of cell death by rapid release H₂S donors Na₂S and NaSH. MPC (A, B) and chondrocytes cultured in alginate (C, D) were exposed to Na₂S, NaSH or the slow release H₂S donor GYY4137 at the concentrations stated for 18 hrs. After this time cell viability was assessed by MTT (A, C) and LDH release (B, D) assays as described in Materials and Methods. MTT data are expressed as percentage of untreated cells. LDH data are expressed as percentage of Triton-X released LDH. Data are expressed as mean ± S.D. of six determinations. *P < 0.05, **P < 0.01, ***P < 0.001, cf. vehicle (PBS)-treated cells.