rdf:type |
|
lifeskim:mentions |
umls-concept:C0005821,
umls-concept:C0015127,
umls-concept:C0016315,
umls-concept:C0045149,
umls-concept:C0237400,
umls-concept:C0300926,
umls-concept:C0332120,
umls-concept:C0332479,
umls-concept:C0392747,
umls-concept:C0439659,
umls-concept:C0596235,
umls-concept:C0597484,
umls-concept:C0678640,
umls-concept:C1314792,
umls-concept:C1383501,
umls-concept:C1510847,
umls-concept:C1879547
|
pubmed:issue |
2
|
pubmed:dateCreated |
1989-5-23
|
pubmed:abstractText |
Although an increase in cytosolic pH (pHi) caused by Na+/H+ exchange enhances Ca2+ mobilization in platelets stimulated by low concentrations of thrombin [Siffert & Akkerman (1987) Nature (London) 325, 456-458], studies using fluorescent indicators for pHi (BCECF) and [Ca2+]i (fura2) suggest that Ca2+ is mobilized while the cytosolic pH decreases. Several lines of evidence indicate that the initial fall in BCECF fluorescence is not due to cytosolic acidification but is caused by a platelet shape change. (1) Pulse stimulation of platelets by successive addition of hirudin (4 unit/ml) and thrombin (0.2 unit/ml) induced a shape change of 43 +/- 8% and a fall in BCECF fluorescence, which both remained unchanged when Na+/H+ exchange was inhibited by ethylisopropylamiloride (EIPA, 100 microM). (2) Increasing the thrombin concentration to 0.4 unit/ml doubled the shape change and the fall in BCECF fluorescence, but again EIPA had no effect on these responses. (3) Treating platelets with 2 microM-ADP induced shape change and a decline in BCECF fluorescence that was unaffected by EIPA. (4) A second addition of thrombin to platelets that had already undergone shape change induced an immediate increase in BCECF fluorescence without a prior decrease. (5) Activation of protein kinase C by 1,2-dioctanoyl-sn-glycerol (DiC8) neither induced shape change nor a decline in BCECF fluorescence; in contrast BCECF fluorescence rapidly increased indicating an immediate cytosolic alkalinization. Concurrent analysis of [Ca2+]i under conditions in which shape change did not interfere with BCECF fluorescence showed that cytosolic alkalinization and Ca2+ mobilization started almost simultaneously. These observations suggest that cytosolic alkalinization is not preceded by a fall in pHi and can support Ca2+ mobilization induced by weak agonists.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2820995,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2826247,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2831223,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2831980,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2831984,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2835100,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2838474,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2855288,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2981834,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-2990447,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3009822,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3013859,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3020026,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3026850,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3027217,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3027576,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3031037,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3031038,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3031039,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3092807,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3115599,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3134885,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3155733,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3434788,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3566711,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3587360,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3653394,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3680230,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3758190,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3838314,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-3934155,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-4050978,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-6087813,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-6315011,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-6621685,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-6710436,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-6815204,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-7318826,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-856039,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2539810-96196
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pubmed:language |
eng
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pubmed:journal |
|
pubmed:citationSubset |
IM
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pubmed:chemical |
|
pubmed:status |
MEDLINE
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pubmed:month |
Mar
|
pubmed:issn |
0264-6021
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pubmed:author |
|
pubmed:issnType |
Print
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pubmed:day |
1
|
pubmed:volume |
258
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
521-7
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
|
pubmed:year |
1989
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pubmed:articleTitle |
Activation of Na+/H+ exchange and Ca2+ mobilization start simultaneously in thrombin-stimulated platelets. Evidence that platelet shape change disturbs early rises of BCECF fluorescence which causes an underestimation of actual cytosolic alkalinization.
|
pubmed:affiliation |
Institut für Physiologie, Ruhr-Universität, Bochum, Federal Republic of Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|