Modification of sodium and potassium channel kinetics by diethyl ether and studies on sodium channel inactivation in the crayfish giant axon membrane

Thesis/Dissertation · Mon Jan 01 00:00:00 EST 1979

DOI:https://doi.org/10.2172/5658026· OSTI ID:5658026

Bean, Bruce Palmer ^[1]

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1. Univ. of Rochester, NY (United States)

The effects of ether and halothane on membrane currents in the voltage clamped crayfish giant axon membrane were investigated. Concentrations of ether up to 300 mM and of halothane up to 32 mM had no effect on resting potential or leakage conductance. Ether and halothane reduced the size of sodium currents without changing the voltage dependence of the peak currents or their reversal potential. Ether and halothane also produced a reversible, dose-dependent speeding of sodium current decay at all membrane potentials. Ether reduced the time constants for inactivation, and also shifted the midpoint of the steady-state inactivation curve in the hyperpolarizing direction. Potassium currents were smaller with ether present, with no change in the voltage dependence of steady-state currents. The activation of potassium channels was faster with ether present. There was no apparent change in the capacitance of the crayfish giant axon membrane with ether concentrations of up to 100 mM. Experiments on sodium channel inactivation kinetics were performed using 4-aminopyridine to block potassium currents. Sodium currents decayed with a time course generally fit well by a single exponential. The time constant of decay was a steep function of voltage, especially in the negative resistance region of the peak current vs voltage relation.The time course of inactivation was very similar to that of the decay of the current at the same potential. The measurement of steady-state inactivation curves with different test pulses showed no shifts along the voltage asix. The voltage-dependence of the integral of sodium conductance was measured to test models of sodium channel inactivation in which channels must open before inactivating; the results appear inconsistent with some of the simplest cases of such models.

• Research Organization: Univ. of Rochester, NY (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: EY-76-C-02-3490
• OSTI ID: 5658026
• Report Number(s): UR-3490-1787
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
ANESTHETICS
BIOLOGICAL EFFECTS
CELL MEMBRANES
ELECTRIC POTENTIAL
PERMEABILITY
ETHYL ETHER
MEMBRANE TRANSPORT
BIOCHEMICAL REACTION KINETICS
INACTIVATION
POTASSIUM COMPOUNDS
SODIUM COMPOUNDS
ANIONS
CRUSTACEANS
EXPERIMENTAL DATA
ISOLATED VALUES
NERVE CELLS
VOLTAGE DROP
ALKALI METAL COMPOUNDS
ANIMAL CELLS
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
CELL CONSTITUENTS
CHARGED PARTICLES
DATA
DATA FORMS
DRUGS
ETHERS
INFORMATION
INVERTEBRATES
IONS
KINETICS
MEMBRANES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
REACTION KINETICS
SOMATIC CELLS
551000* - Physiological Systems
550200 - Biochemistry