Factors determining the plasma-membrane potential of lymphocytes.
1. Lymphocytes from pig mesenteric lymph node have low permeability to K+ (Rb+), Na+ and Cl-. None of these ions is in Nernst equilibrium with the plasma-membrane potential (delta psi p). 2. delta psi p can be calculated from the transmembrane distribution of the permeant cation methyltriphenylphosphonium (TPMP+) in the presence of the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) to abolish uptake into intracellular mitochondria. In normal culture medium delta psi p is 56 mV. 3. A similar potential is found in T-enriched pig cells and in mouse thymocytes. 4. The contribution of electrogenic (Na+ + K+)ATPase to delta psi p is about 7 mV. 5. The remainder of the lymphocyte delta psi p is a polyionic potential set up by K+ and Cl- with a permeability coefficient for Cl- of similar magnitude to that for K+.
D000818:Animals; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D002712:Chlorides / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D008954:Models, Biological; D009861:Onium Compounds; D012413:Rubidium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013552:Swine; D013816:Thermodynamics; D014320:Triphenylmethyl Compounds / Q000378:metabolism
D002712:Chlorides; D009861:Onium Compounds; D014320:Triphenylmethyl Compounds; C011561:triphenylmethylphosphonium; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium