ADH-evoked [Cl-]i-dependent transient in whole cell current of distal nephron cell line A6.
The effect of antidiuretic hormone (ADH) on a distal nephron cell line (A6) was studied using the whole cell patch-clamp technique. A6 cells were cultured on a permeable support filter for 10-14 days in media containing 10% fetal bovine serum without supplemental aldosterone. In the unstimulated condition A6 cells had very small conductances of Na+,K+, and Cl-. Arginine vasotocin (AVT, 140 mU/ml, 280 nM) evoked a "transient" increase in whole cell currents as did dibutyryl-adenosine 3',5'-cyclic monophosphate (5 mM). These transients consisted of two components; one was the nonselective cation conductance, and the other was the Cl- conductance. Activation of these conductances was dependent on intracellular Cl- concentration ([Cl-]i). At low [Cl-]i (< or = 50 mM) both conductances were activated, whereas when [Cl-]i was 80 mM, only the Cl- conductance was activated. At high [Cl-]i (125 mM), both conductances were inhibited. It seems likely that the [Cl-]i maintained at a low level (< or = 50 mM) is an important requirement for A6 cells to respond to AVT.
Division of Respiratory Research, Hospital for Sick Children, Toronto, Ontario, Canada.
T
T
Nakahari
Y
Y
Marunaka
D000818:Animals; D001464:Barium / Q000494:pharmacology; D002417:Cattle; D002460:Cell Line; D002712:Chlorides / Q000378:metabolism*; D005682:Gadolinium / Q000494:pharmacology; D008536:Meglumine / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects*; D009399:Nephrons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques; D013997:Time Factors; D014667:Vasopressins / Q000494:pharmacology*; D014668:Vasotocin / Q000494:pharmacology*
D002712:Chlorides; D014667:Vasopressins; D001464:Barium; D008536:Meglumine; D005682:Gadolinium; C038958:gadolinium chloride; D014668:Vasotocin