ATP-activated single-channel currents recorded from cell-free patches of pheochromocytoma PC12 cells.
Single-channel recordings were made using cell-free membrane patches (outside-out configuration) isolated from pheochromocytoma PC12 cells. ATP (50 microM) activated single channel currents in the isolated patches and the currents inactivated with a half-decay time of about 5s. The single channel conductance was about 13 pS in external solution with 140 mM Na. The amplitudes of the single-channel currents were decreased when external Ca was increased from 1.8 to 16.2 mM, suggesting that Ca blocks ion permeation through the channel. These properties of single-channel currents may underlie those of the macroscopic current.
Nakazawa
K
K
Division of Pharmacology, National Institute of Hygienic Sciences, Tokyo, Japan.
Inoue
K
K
Fujimori
K
K
Takanaka
A
A
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000310:Adrenal Gland Neoplasms / Q000473:pathology / Q000503:physiopathology*; D002118:Calcium / Q000378:metabolism; D002474:Cell-Free System / Q000502:physiology; D004553:Electric Conductivity; D004594:Electrophysiology; D005110:Extracellular Space / Q000378:metabolism; D007473:Ion Channels / Q000502:physiology*; D009994:Osmolar Concentration; D010673:Pheochromocytoma / Q000473:pathology / Q000503:physiopathology*; D014407:Tumor Cells, Cultured
D007473:Ion Channels; D000255:Adenosine Triphosphate; D002118:Calcium