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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1986-12-3
|
| pubmed:abstractText |
Guanosine 5'-[gamma-thio]triphosphate and guanosine 5'-[beta,gamma-imido]triphosphate enhance Ca2+-dependent 5-hydroxytryptamine secretion from electropermeabilised human platelets. GTP has little such effect except when the platelets are permeabilised, and incubated with this nucleotide, at 2 degrees C and pH 7.4. The lag phase observed in the time course of 5-hydroxytryptamine secretion induced by addition of guanosine 5'-[gamma-thio]triphosphate is markedly longer than that characterising secretion induced by Ca2+ alone, by thrombin +/- GTP or by guanosine 5'-[gamma-thio]triphosphate in the presence of thrombin. GTP causes competitive inhibition of the enhancement of the Ca2+-dependent secretory response induced by guanosine 5'-[gamma-thio]triphosphate when both nucleotides are added simultaneously. The extent of inhibition is decreased if guanosine 5'-[gamma-thio]triphosphate is added prior to GTP. GTP markedly enhances the effect of thrombin on Ca2+-dependent 5-hydroxytryptamine secretion by increasing the maximal extent of the response and decreasing the thrombin concentration required to give half-maximal response. A similar effect is observed on addition of guanosine 5'-[gamma-thio]triphosphate in the presence of thrombin at short incubation times. On more prolonged incubation the effects of thrombin and guanosine 5'-[gamma-thio]triphosphate are additive. Guanosine 5'-[beta-thio]diphosphate completely inhibits the response induced by guanosine 5'-[gamma-thio]triphosphate or guanosine 5'-[beta,gamma-imido]triphosphate but has little effect on the response induced by Ca2+ when added alone or in the presence of thrombin. Partial inhibition is observed for the response induced by thrombin + GTP. Cyclic-AMP effectively inhibits the response induced by thrombin + GTP but has little effect on that induced by guanosine 5'-[gamma-thio]triphosphate or guanosine 5'-[beta,gamma]imidotriphosphate. The results provide further support for the proposal [Haslam, R.J. & Davidson, M.M.L. (1984) FEBS Lett. 170, 90-95], that receptor--phospholipase-C coupling in platelets is mediated in part by a guanine-nucleotide-binding (Np) protein but that a coupling mechanism may also exist which is independent of such a protein. The properties of guanine-nucleotide-dependent coupling resemble those previously described for receptor--adenylate-cyclase coupling.
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| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Guanine Nucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Serotonin,
http://linkedlifedata.com/resource/pubmed/chemical/Thrombin
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0014-2956
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
160
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
183-90
|
| pubmed:dateRevised |
2007-7-23
|
| pubmed:meshHeading |
pubmed-meshheading:3021450-Blood Platelets,
pubmed-meshheading:3021450-Calcium,
pubmed-meshheading:3021450-Cell Membrane Permeability,
pubmed-meshheading:3021450-Cyclic AMP,
pubmed-meshheading:3021450-Electricity,
pubmed-meshheading:3021450-Guanine Nucleotides,
pubmed-meshheading:3021450-Guanosine Triphosphate,
pubmed-meshheading:3021450-Humans,
pubmed-meshheading:3021450-Serotonin,
pubmed-meshheading:3021450-Thrombin
|
| pubmed:year |
1986
|
| pubmed:articleTitle |
Effects of guanine nucleotides on the properties of 5-hydroxytryptamine secretion from electropermeabilised human platelets.
|
| pubmed:publicationType |
Journal Article
|