Down-regulation of the sodium pump following chronic exposure of HeLa cells and chick embryo heart cells to ouabain.
1 HeLa cells and primary cultures of embryonic chick heart cells were grown in medium containing low concentrations of ouabain for 24 h. 2 Compared with normal cells, cells grown in ouabain have fewer free sodium pump sites, an increased intracellular sodium concentration and a decreased intracellular potassium concentration. The cells are able to maintain their intracellular ion contents because the remaining pump sites have an increased turnover rate. 3 When cells that have been chronically exposed to ouabain are returned to normal growth medium, the sodium pump site numbers increase; the recovery process begins within 6 to 8 h and is complete within 24 h. Recovery of pump site numbers is primarily dependent upon de novo protein synthesis since the protein synthesis inhibitor, cycloheximide, prevents recovery.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002642:Chick Embryo; D006367:HeLa Cells; D006801:Humans; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D010042:Ouabain / Q000378:metabolism / Q000494:pharmacology*; D011868:Radioisotopes; D012413:Rubidium; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors
D011868:Radioisotopes; D010042:Ouabain; D012964:Sodium; D012413:Rubidium