Effect of H₂S on intracellular Ca²⁺ concentration in HSCs under H₂O₂^-induced oxidative stress conditions 

Objective To determine the effects of H2S on rat primary hepatic stellate cell (HSC) proliferation and intracellular calcium (i) concentration and to investigate the underlying mechanisms of these effects.Methods An in vitro model of oxidative stress-induced hepatic fibrosis was established by exposing rat primary HSCs to H2O2.The induced HSCs were loaded with Fluo-3/AM and treated with a KATP channel inhibitor (glyburide) and different concentrations of an H2S donor (NaSH) .The Ca2+ concentration was measured by laser scanning confocal microscopy and the HSC proliferation rate at different H2S concentrations was measured by the CCK-8 assay.Results Exposure to a low concentration of H2S (100 μmo/L NaSH) significantly decreased the i level (P<0.05) and inhibited proliferation of HSCs.KATP channel inhibition blocked the effects of H2S.In contrast, exposure to high concentration of H2S (1 mmo/L NaSH) significantly increased i (P<0.05) and promoted proliferation of HSCs.Conclusion Stimulation of the KATP channel in HSCs by low and high concentrations of H2S produce opposite effects on both i and proliferation.