Extracellular pH selectively modulates recovery from sodium inactivation in frog myelinated nerve.
The Hodgkin-Huxley kinetic parameters, alpha h and beta h, which govern the rate of recovery from and development of sodium channel inactivation, respectively, have been measured as a function of membrane potential and external pH using a three-pulse protocol. alpha h but not beta h is substantially accelerated by reducing external pH from 7.4 to 6.4. The alpha h vs. voltage curve appears to be selectively shifted in the depolarizing direction by approximately 12 mV for this pH change, giving an apparent, h infinity curve shift of approximately 6 mV in the same direction (less inactivation).
D000818:Animals; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D009186:Myelin Sheath / Q000187:drug effects / Q000502:physiology*; D011892:Rana catesbeiana; D012584:Sciatic Nerve / Q000187:drug effects / Q000502:physiology*; D012964:Sodium / Q000494:pharmacology*
D012964:Sodium