Inactivation of sodium channels: second order kinetics in myelinated nerve
نویسندگان
چکیده
منابع مشابه
Potassium Channels in Myelinated Nerve
The permeability of K channels to various cations is studied in myelinated nerve. Ionic currents under voltage clamp are measured in Ringer solution containing tetrodotoxin and a high concentration of the test ion. Reversal potentials for current in K channels are determined and used with the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The ratios P(Tl):P(K):P(Rb):P(NHNH4...
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Recently it has been established that y toxin of Tityus serrulatus scorpion venom has a very high affinity to Na channels and can be successfully used as a marker during their purification from excitable membranes (Barhanin et al. 1983 ; Grishin 1983). There has, however, been some controversy concerning the effects of the y toxin on properties of Na channels in different tissues. Thus, in neur...
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The properties of voltage-dependent Na channels modified by veratridine (VTD) were studied in voltage-clamped nodes of Ranvier of the frog Rana pipiens. Two modes of gating of VTD-modified channels are described. The first, occurring on a time scale of milliseconds, is shown to be the transition of channels between a modified resting state and a modified open state. There are important qualitat...
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The permeability of K channels to various cations is studied in myelinated nerve. Ionic currents under voltage clamp are measured in Ringer solution containing tetrodotoxin and a high concentration of the test ion. Reversal potentials for current in K channels are determined and used with the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The ratios PTI:PK:PRb:PNH4 are 2.3:...
متن کاملIndependent Versus Coupled Inactivation in Sodium Channels
The voltage sensor of the sodium channel is mainly comprised of four positively charged S4 segments. Depolarization causes an outward movement of S4 segments, and this movement is coupled with opening of the channel. A mutation that substitutes a cysteine for the outermost arginine in the S4 segment of the second domain (D2:R1C) results in a channel with biophysical properties similar to those ...
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ژورنال
عنوان ژورنال: The Journal of Physiology
سال: 1977
ISSN: 0022-3751
DOI: 10.1113/jphysiol.1977.sp012111