Cyclic GMP-activated channel activity in renal epithelial cells (A6).
We studied the effects of guanosine 3',5'-cyclic monophosphate (cGMP) and nitroprusside on ion channels in the apical membrane of confluent A6 cells (a distal nephron cell line) cultured on permeable supports for 10-14 days using patch clamp techniques. In cell-attached patches without any detectable channel activity, activity of a non-selective cation channel with a single-channel conductance of 1 pS was observed after adding nitroprusside. After adding cGMP to the cytosolic surface of inside-out patches with no detectable channel activity, we observed single channel activity similar to the channel observed after adding nitroprusside. These observations imply that nitroprusside activates a non-selective cation channel with small single channel conductance (1 pS) via an increase in cGMP which activates the channel.
Marunaka
Y
Y
Department of Physiology, Emory University School of Medicine, Atlanta, GA.
Ohara
A
A
Matsumoto
P
P
Eaton
D C
DC
D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000502:physiology*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007668:Kidney / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008564:Membrane Potentials; D009599:Nitroprusside / Q000494:pharmacology
D007473:Ion Channels; D009599:Nitroprusside; D006152:Cyclic GMP