Cardiac sodium channel Markov model with temperature dependence and recovery from inactivation

Biophys J. 1999 Apr;76(4):1868-85. doi: 10.1016/s0006-3495(99)77346-7.

Abstract

A Markov model of the cardiac sodium channel is presented. The model is similar to the CA1 hippocampal neuron sodium channel model developed by Kuo and Bean (1994. Neuron. 12:819-829) with the following modifications: 1) an additional open state is added; 2) open-inactivated transitions are made voltage-dependent; and 3) channel rate constants are exponential functions of enthalpy, entropy, and voltage and have explicit temperature dependence. Model parameters are determined using a simulated annealing algorithm to minimize the error between model responses and various experimental data sets. The model reproduces a wide range of experimental data including ionic currents, gating currents, tail currents, steady-state inactivation, recovery from inactivation, and open time distributions over a temperature range of 10 degrees C to 25 degrees C. The model also predicts measures of single channel activity such as first latency, probability of a null sweep, and probability of reopening.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Algorithms
  • Animals
  • Biophysical Phenomena
  • Biophysics
  • Ion Channel Gating
  • Kinetics
  • Markov Chains
  • Membrane Potentials
  • Models, Cardiovascular*
  • Myocardium / metabolism*
  • Sodium Channel Blockers*
  • Sodium Channels / metabolism*
  • Temperature
  • Thermodynamics

Substances

  • Sodium Channel Blockers
  • Sodium Channels