Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
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.
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
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0264-6021
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
521-7
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1989
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.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't