Document Detail

Membrane capacitance in hyperpolarized muscle fibres.
MedLine Citation:
PMID:  6974237     Owner:  NLM     Status:  MEDLINE    
1. Voltage clamp experiments on muscle fibres compared transients to 10 mV steps at hyperpolarized voltages between VT = -100 to -185 mV with controls obtained at VC = -85 mV. 2. Membrane capacitance fell by 15%, 13% and 4.5% per 100 mV hyperpolarization fro -85 mV in hypertonic low chloride, hypertonic high chloride and isotonic high chloride-containing solutions respectively. 3. The charge moved by the 'on' and 'off' parts of the applied step was equal over the voltages studied. This suggests that the changes were capacitative rather than ionic in origin. The changes could not be explained in terms of the cable properties of the transverse tubular system. They may therefore reflect non-linear capacitance in the muscle membrane itself. 4. Subtracting control transients at -85 mV from transients obtained at different voltages gave monotonically decaying charge movements. In the frequency domain, these charge movements possessed real and imaginary permittivities resembling those of a 'Debye' particle. 5. It is concluded that muscle membranes have non-linear capacitances even at voltages far hyperpolarized to those in which familiar voltage-dependent processes occur.
C L Huang
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of physiology     Volume:  313     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  1981  
Date Detail:
Created Date:  1981-11-24     Completed Date:  1981-11-24     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  207-22     Citation Subset:  IM    
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MeSH Terms
Chlorides / pharmacology
Electric Conductivity
Hypertonic Solutions
Isotonic Solutions
Membrane Potentials / drug effects
Muscles / drug effects,  physiology*
Rana temporaria
Reg. No./Substance:
0/Chlorides; 0/Hypertonic Solutions; 0/Isotonic Solutions

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