title: Na and K dependence of the Na/K pump in cystic fibrosis fibroblasts.
abstract: The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fibrosis, the Na/K pump had a significantly lower affinity for K (Km = 1.6 mM) when compared to normals (Km = 0.9 mM). This difference was demonstrated by using two independent experimental designs.
mesh_terms: D000293:Adolescent; D000328:Adult; D001693:Biological Transport, Active / Q000187:drug effects; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D012413:Rubidium / Q000378:metabolism; D012867:Skin / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D010042:Ouabain; D012964:Sodium; D012413:Rubidium; D011188:Potassium