Ouabain-resistant, amiloride-sensitive Na+-K+ pumping activity and morphological changes are inducible.
The functional expression of a ouabain-resistance gene has been studied in a transfected cell line, OR-6 cells. These cells possess a ouabain-inhibitable, amiloride-resistant Na+-K+ pump under control conditions. They can be induced by brief culture in the presence of low concentrations of ouabain to express a ouabain-resistant, amiloride-sensitive Na+-K+ pumping activity. They revert to the uninduced phenotype shortly after removal of ouabain from the culture medium. When placed in low-potassium, low-serum, or dibutyryl adenosine 3'-5'-cyclic monophosphate-containing media, these cells produce long cellular extensions. Thus a single inducible gene appears to regulate sensitivity of the Na+-K+ pumping activity to cardiac glycosides and to amiloride, and it may be related to important characteristics of cellular morphology.
Epstein
J A
JA
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
Lechene
C
C
D000584:Amiloride / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active; D002460:Cell Line; D004351:Drug Resistance / Q000235:genetics; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D007473:Ion Channels; D010042:Ouabain; D000584:Amiloride; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium