H2S and HS- donor NaHS inhibits intracellular chloride channels

We have characterized the effect of H2S on single channel properties of the chloride channels derived from the rat heart lysosomal vesicles incorporated into a bilayer lipid membrane. The single chloride channel currents were measured in 250: 50 mmol/l KCl cis/trans solutions. H2S inhibited the chloride channels by decreasing the channel open probability in a concentration-dependent manner. The inhibitory effect of H2S was side-dependent with the IC50 values of 42 and 75 mu mol/l for the trans and the cis sides, respectively. The mixture of H2S with the NO donor S-nitroso-N-acetyl-DL-penicillamine had smaller effect (IC50 = 180 mu mol/l) than H2S alone. We assume that the inhibitory effect of H2S on chloride channels may be responsible for some of its numerous biological effects.