Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-8-27
pubmed:abstractText
Using the giant patch technique, we combined two fast relaxation methods on excised patches from guinea pig cardiomyocytes to compare the rate constants of the involved reaction steps. Experiments were done in the absence of intra- or extracellular K+. Fast ATP concentration jumps were generated by photolysis of caged ATP at pH 6.3 with laser flash irradiation at a wavelength of 308 nm and 10 ns duration, as described previously. Transient outward currents with a fast rising phase, followed by a slower decay and a small stationary current, were obtained. Voltage pulses were applied to the same patch in the presence or absence of intracellular ATP. Subtraction of the voltage jump-induced currents in the absence of ATP from those taken in the presence of ATP yielded monoexponential transient current signals, which were dependent on external Na+ but did not differ between intracellular pH (pHi) values 6.3 or 7.4. Rate constants showed a characteristic voltage dependence, i.e., saturating at positive potentials (approximately 200 s-1, 24 degrees C) and exponentially rising with increasing negative potentials. Rate constants of the fast component from transient currents obtained after an ATP concentration jump agree well with rate constants from currents obtained after a voltage jump to zero or positive potentials (pHi 6.3), and the two exhibit the same activation energy of approximately 80 kJ.mol-1. For a given membrane patch, the amount of charge that is moved across the plasma membrane is roughly the same for each of the two relaxation techniques.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-1333148, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-1335502, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-148906, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2430183, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2512567, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2543461, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2544655, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2552127, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2607333, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-2824243, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-3004932, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-3016280, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-3038187, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-3041002, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-3041003, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-6089192, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-6545637, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-7177773, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8011923, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8035166, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8128223, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8270908, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8382257, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8519991, http://linkedlifedata.com/resource/pubmed/commentcorrection/9199783-8913588
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
73
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
186-94
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Comparison of Na+/K(+)-ATPase pump currents activated by ATP concentration or voltage jumps.
pubmed:affiliation
Johann Wolfgang Goethe-Universität Frankfurt am Main, Germany.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't