H2S and HS– donor NaHS inhibits intracellular chloride channels

Abstract

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.