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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1993-5-25
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pubmed:abstractText |
Platelets in plasma were loaded with the probe BCECF/AM, and changes in cytoplasmic pH levels induced by highly purified human alpha-thrombin (2900 NIH U/mg) were studied in washed platelets having high- and moderate-affinity receptors and in platelets from which the high-affinity alpha-thrombin receptor had been removed by treatment with Serratia marcescens protease. In intact platelets, cytoplasmic acidification reached a maximum within 2 minutes of -0.072 +/- 0.009 pH units at 0.3 nmol/L alpha-thrombin concentration (0.03 U/ml). Cytoplasmic pH values were higher at both lower and higher alpha-thrombin concentrations and were significantly (p = 0.018) higher at 2 nmol/L alpha-thrombin, which induced -0.037 +/- 0.013 pH units of acidification. Five nanomoles of alpha-thrombin, however, induced cytoplasmic alkalinization of +0.027 +/- 0.033 pH units. In platelets lacking the high-affinity receptor where there is a 10 to 20-fold reduction in sensitivity to alpha-thrombin, acidification reached a maximum of -0.175 +/- 0.033 pH units at 2 nmol/L alpha-thrombin, but alkalinization was observed at 5 nmol/L (+0.038 +/- 0.025) and 10 nmol/L (+0.042 +/- 0.007) alpha-thrombin. These results show that the transition from acidification to alkalinization occurs in the same range of alpha-thrombin concentrations (2 to 5 nmol/L) in both preparations, despite the rightward shift in sensitivity caused by the absence of the high-affinity receptor. However, the maximum acidification reached in control platelets (-0.037 pH units at 2 nmol/L) was much less than the value obtained in platelets lacking the high-affinity receptor (-0.175 pH units at 2 nmol/L alpha-thrombin).(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Thrombin,
http://linkedlifedata.com/resource/pubmed/chemical/Thrombin,
http://linkedlifedata.com/resource/pubmed/chemical/ethylisopropylamiloride
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pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0022-2143
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
121
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
662-7
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8386738-Amiloride,
pubmed-meshheading:8386738-Blood Platelets,
pubmed-meshheading:8386738-Cytoplasm,
pubmed-meshheading:8386738-Humans,
pubmed-meshheading:8386738-Hydrogen-Ion Concentration,
pubmed-meshheading:8386738-Platelet Activation,
pubmed-meshheading:8386738-Receptors, Cell Surface,
pubmed-meshheading:8386738-Receptors, Thrombin,
pubmed-meshheading:8386738-Thrombin
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pubmed:year |
1993
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pubmed:articleTitle |
Changes in cytoplasmic pH in platelets activated through the high- and moderate-affinity receptor pathways by highly purified human alpha-thrombin.
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pubmed:affiliation |
Cell Biology Department, American Red Cross, Rockville, MD 20855.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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