Adenosine triphosphate-activated inward current in isolated smooth muscle cells from rat vas deferens

Pflugers Arch. 1987 Aug;409(6):644-6. doi: 10.1007/BF00584668.


The electrophysiological effect of adenosine triphosphate (ATP) on the enzymatically dispersed smooth muscle cells from rat vas deferens was investigated. ATP always induced depolarization accompanied with a reduction in membrane resistance. In a whole cell voltage clamp experiment, an inward current was recorded when the cell was exposed to ATP-containing solution. The ATP-induced current disappeared within 2 min even in the continuous presence of ATP, which may indicate that the cells were desensitized to this compound. The ATP-induced current was also recorded in the cells superfused with 10(-5) M nicardipine or in the Cs-loaded cells, eliminating the possible involvement of voltage-gated Ca and K current. During cell-attached patch clamp, an elementary current having a mean conductance of 20 pS was observed when the intrapipette solution was changed to ATP-containing solution. The estimated zero current potentials of the ATP-activated macroscopic current and elementary current were about 0 mV. These results suggest that ATP exerts its transmitter-like action by activating ion channels in smooth muscles.

MeSH terms

  • Adenosine Triphosphate / pharmacology*
  • Animals
  • Cations / metabolism
  • In Vitro Techniques
  • Ion Channels / drug effects*
  • Male
  • Membrane Potentials / drug effects
  • Muscle, Smooth / cytology
  • Muscle, Smooth / drug effects*
  • Nicardipine / pharmacology
  • Rats
  • Vas Deferens / drug effects


  • Cations
  • Ion Channels
  • Adenosine Triphosphate
  • Nicardipine