1986 Volume 53 Issue 2 Pages 159-173
The effects of intracellular acidification on the electrical activity of single ventricular cell were examined by internal dialysis technique through a patch clamp pipette.
Mild intracellular acidification (pHpip6.0)evoked a time-independent outward current and stronger acidification(pHpip5.0) caused reduction of all current systems of the membrane including the evoked outward current.The pHpip6.0-induced current was specific tointracellular acidification and was separated into twocomponents by thedifference of the effects of Cd2+ and Ba2+.Both components of the current could be diminished with the replacement of intracellular K+toCs+ and may be also carried byK+. A block of current systems by mild intracellular acidification (pHpip6.0) was confirmed in the case of the inward-rectifier K+ channel using a single channel recording in the inside-out patch.The ineffectiveness of low pHi(pHpip6.0)in the whole cell experiment could be explained by the existence of Na-H exchange system at the cell membrane, since even pHpip6.8could suppress the membrane current under Na-free Tyrodesolution.
