title: Intracellular potassium activity, potassium equilibrium potential and membrane potential of carotid body glomus cells.
abstract: The intracellular potassium activity (ai(K)) of glomus cells in isolated rabbit carotid bodies was measured with potassium ion selective microelectrodes (K+ electrodes). The measurements yielded a mean ai(K) value of 33.0 mM in Hepes-buffered Tyrode's solution equilibrated with 100% O2. This value is significantly higher than that predicted by assuming that K+ ions are passively distributed across the membrane of glomus cells. The relationship between the membrane potential (EM) and the equilibrium potential of K+ ions (EK) at various extracellular potassium activities (ao(K] suggests that K+ ions are not involved in the maintenance of the carotid body glomus cell EM.
mesh_terms: D000818:Animals; D002344:Carotid Body / Q000502:physiology*; D002463:Cell Membrane Permeability; D066298:In Vitro Techniques; D008564:Membrane Potentials; D011188:Potassium / Q000378:metabolism / Q000502:physiology*; D011817:Rabbits
chemical_list: D011188:Potassium