title: Increased ouabain-sensitive 86Rb+ uptake and sodium and potassium ion-activated adenosine triphosphatase activity in transformed cell lines.
abstract: During the log phase of growth both the active, ouabain-sensitive K+ uptake, measured as 86Rb+, and the sodium and potassium ion-activated ATPase ((Na+ + K+)-ATPase) activity of SV40-transformed 3T3 cells were 2.5-and 5,5-fold higher, respectively, than in untransformed 3T3 cells. A similar higher active K+ uptake was found for Rous sarcoma virus and SV40-transformed baby hamster kidney cells compared with untransformed BHK cells. The active K+ uptake in SV403T3 and normal 3T3 cells decreased when the growth rate of both cell types diminished. Reduction in ouabain-sensitive ATP hydrolysis only occurred later, however, when appreciable decreases in cell viability were seen. Arrhenius plots of the (Na+ + K+)-ATPase activity of SV403T3 cells indicated a discontinuity at 24 degrees, whereas no similar discontinuity was indicated for 3T3 cells. The consequences of elevated K+ transport and (Na+ + K+)-ATPase activity in transformed cells and the possibility that the increased activity might be related to differences inphospholipid fatty acyl chain fluidity are discussed.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001358:Avian Sarcoma Viruses; D001665:Binding Sites; D001693:Biological Transport, Active; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002999:Clone Cells; D006224:Cricetinae; D004789:Enzyme Activation / Q000187:drug effects; D007668:Kidney; D051379:Mice; D008807:Mice, Inbred BALB C; D010042:Ouabain / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology*; D011485:Protein Binding; D011868:Radioisotopes; D012413:Rubidium / Q000378:metabolism*; D013539:Simian virus 40; D012964:Sodium / Q000494:pharmacology*
chemical_list: D011868:Radioisotopes; D010042:Ouabain; D012964:Sodium; D000251:Adenosine Triphosphatases; D012413:Rubidium; D011188:Potassium