title: The blood: bone disequilibrium. I. The active accumulation of K+ into the bone extracellular fluid.
abstract: The role of periosteal and endosteal cellular envelopes in the control of the K+ and Na+ content of embryonic chick calvaria was investigated. Data have been presented which suggest that the K+ in extracellular fluid of calvaria may be under a direct membrane control similar to the pump-leak systems hypothesized for most cells. Based on DNA and K+ analysis of cell water, volume and DNA content, the K+ in the bone extracellular fluid was calculated to account for 75% of the total K+ content of intact calvaria. The bulk of K+ is therefore extracellular and its accumulation there was found to be sensitive to the presence of ouabain, iodoacetate, CCCP, and to temperature. Losses of 70% of calvaria K+ were found one hour after addition of 250 muM ouabain. If the exposure to ouabain was brief, the K+ loss was partially reversed. The rate of 42K+ uptake was found to be depressed by ouabain, decreased pH, and La2+. The total Na+ content of these calvaria was found not to vary when incubated with ouabain, iodoacetate, or CCCP.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D001769:Blood; D001842:Bone and Bones / Q000166:cytology / Q000378:metabolism*; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D002478:Cells, Cultured; D002642:Chick Embryo; D003080:Cold Temperature; D004247:DNA / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D006651:Histocytochemistry; D007461:Iodoacetates / Q000494:pharmacology; D008954:Models, Biological; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
chemical_list: D007461:Iodoacetates; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D010042:Ouabain; D004247:DNA; D012964:Sodium; D011188:Potassium