title: First order phase transition and hysteresis in a cell's maintenance of the membrane potential--An essential role for the inward potassium rectifiers.
abstract: Hysteretic behavior is found experimentally in the transmembrane potential at low extracellular potassium in mouse lumbrical muscle cells. Adding isoprenaline to the external medium eliminates the bistable, hysteretic region. The system can be modeled mathematically and understood analytically with and without isoprenaline. Inward rectifying potassium channels appear to be essential for the bistability. Relations are derived to express the dimensions of the bistable area in terms of system parameters. The selective advantage and evolutionary origin of inward rectifying channels and hysteretic behavior is discussed.
authors.affiliation: Dept. of Physics, East Carolina University, Greenville, NC 27858, USA. jag0504@ecu.edu
authors.forename: Jill
authors.initials: J
authors.lastname: Gallaher
authors.forename: Martin
authors.initials: M
authors.lastname: Bier
authors.forename: Jan Siegenbeek
authors.initials: JS
authors.lastname: van Heukelom
mesh_terms: D000818:Animals; D004563:Electrochemistry; D007545:Isoproterenol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000166:cytology* / Q000502:physiology; D011188:Potassium / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism*
chemical_list: D024661:Potassium Channels, Inwardly Rectifying; D007545:Isoproterenol; D011188:Potassium