H(2)S and HS(-) donor NaHS inhibits intracellular chloride channels.

We have characterized the effect of H(2)S 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. H(2)S inhibited the chloride channels by decreasing the channel open probability in a concentration-dependent manner. The inhibitory effect of H(2)S was side-dependent with the IC(50) values of 42 and 75 micromol/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 (IC(50) = 180 micromol/l) than H(2)S alone. We assume that the inhibitory effect of H(2)S on chloride channels may be responsible for some of its numerous biological effects.