rdf:type |
|
lifeskim:mentions |
|
pubmed:dateCreated |
1992-9-2
|
pubmed:abstractText |
1. Unitary Na+ channel currents were recorded from isolated guinea-pig ventricular myocytes using the cell-attached patch-clamp technique with high [Na+] in the pipette to enhance the signal-to-noise ratio. 2. The probability that the channel enters the inactivated state (I) directly from resting states (C) was investigated over a wide range of membrane potentials. 3. At membrane potentials of -60 mV or more positive, Markov chain theory was used to estimate the probability of C----I from histograms of the number of channel openings per depolarizing period. Holding potentials at least as negative as -136 were required to ensure that all channels resided in C prior to depolarization. 4. At membrane potentials negative to -60 mV, a two-pulse protocol was employed to determine the probability of C----I from the fraction of blank sweeps during the pre-pulse with correction for missed events. 5. The probability of C----I was found to be steeply voltage dependent at negative potentials, falling from 0.87 +/- 0.03 (mean +/- S.D.) at -91 mV to 0.42 +/- 0.01 at -76 mV. At potentials positive to -60 mV, this probability was less steeply voltage dependent and decayed to near zero at 0 mV. 6. Under physiological conditions, C----I transitions may produce appreciable Na+ channel inactivation at diastolic potentials. At potentials above the action potential threshold, inactivation is much more likely to occur from the open state.
|
pubmed:grant |
|
pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-12991237,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-14946715,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2154132,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2157791,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2172443,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2212978,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2299331,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2415670,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2421791,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2423151,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2434628,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2435840,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2438373,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2439231,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2443658,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2506548,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2540529,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2543931,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2551998,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2554301,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2559976,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-2561792,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-3217234,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-3607218,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-5025744,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-5120393,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-536736,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-591911,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6094704,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6247484,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6268217,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6270629,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6316158,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-6327148,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-7320902,
http://linkedlifedata.com/resource/pubmed/commentcorrection/1668345-7381770
|
pubmed:language |
eng
|
pubmed:journal |
|
pubmed:citationSubset |
IM
|
pubmed:chemical |
|
pubmed:status |
MEDLINE
|
pubmed:month |
Nov
|
pubmed:issn |
0022-3751
|
pubmed:author |
|
pubmed:issnType |
Print
|
pubmed:volume |
443
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
629-50
|
pubmed:dateRevised |
2009-11-18
|
pubmed:meshHeading |
|
pubmed:year |
1991
|
pubmed:articleTitle |
Sodium channel inactivation from resting states in guinea-pig ventricular myocytes.
|
pubmed:affiliation |
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|