Linked Life Data

2820494

Source:http://linkedlifedata.com/resource/pubmed/id/2820494

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1987-11-9
pubmed:abstractText
Thrombin stimulation of human platelets initiates a membrane depolarization attributable to a Na+ influx into, and an alkalinization of, the cytoplasm, both of which follow a similar rapid time scale and thrombin-dose dependence. These responses precede secretion of the contents of the dense granules (serotonin) and, after 1 minute, of lysosomes (beta-glucuronidase). We have evaluated these parameters in the presence of 2H2O in order to determine if the Na+ influx and H+ efflux are sequential or simultaneous. NMR evidence indicates that 2H2O equilibration in rapid, and virtually complete within the 3 min prestimulation platelet equilibration period. In response to an 0.05 U/ml addition of thrombin, the rate of depolarization is 70-80% slower in 2H2O than in H2O. The time to reach maximal depolarization is 5 to 10 seconds longer in 2H2O, the extent of depolarization 60% inhibited, and the pH change 85% inhibited. The serotonin secretion is unaltered, while the beta-glucuronidase secretion is 130-180% enhanced. Dimethylamiloride inhibits the Na+ influx and the pH change completely. These results suggest that the Na+ and H+ fluxes across the plasma membrane are interdependent but neither simultaneous nor electroneutral. Furthermore, granule secretion, previously shown by us to be independent of the existent Na+ gradient, depends on the cytoplasmic K+ and H+ concentrations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
903
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
381-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Sequential sodium-proton exchange in thrombin-induced human platelets.
pubmed:affiliation
Department of Biochemistry, Boston University School of Medicine, MA 02118.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.