With the patch clamp method we demonstrate a stretch-sensitive Cl- currents as well as stretch-sensitive Cl- channels in a small group (5%,n 117) of cultured human corpus cavernosal muscle cells. The current and the channel activities had the following characteristics: (1) Their equilibrium potentials changed with extracellular Cl- concentration close to that predicted by Nernst equation provided that the relevant channels had high permeability to Cl- but low permeability to acetate ions; (2) They were blocked by mM concentrations of Zn2+; (3) The i-v relation of single channel current was almost linear for holding potentials varied from -70 to +60 mV; and (4) The channels had unitary conductances of approximately 140-170 pS.