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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
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pubmed:dateCreated |
1989-5-11
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pubmed:abstractText |
The MgATP dependency of secretion was investigated in digitonin-permeabilized adrenal chromaffin cells. Shortly after permeabilization there is a component of Ca2+-dependent secretion that occurs in the absence of MgATP in the medium. This secretion occurs from cells which are permeable to Ca2+/[ethylene-bis(oxyethylenenitrilo)]tetraacetic acid buffers, to nucleotides, and to proteins. It is prevented by treatment of cells with metabolic inhibitors to reduce cellular ATP prior to permeabilization. The rate of MgATP-independent secretion is rapid and terminates by approximately 2 min after introduction of Ca2+. MgATP-independent secretion is labile and is lost unless Ca2+ is introduced within 8 min of permeabilization. MgATP-dependent secretion occurs at a slower rate than MgATP-independent secretion and continues at a constant rate for 12 min. Preincubation of permeabilized cells with MgATP enhances Ca2+-dependent secretion during a subsequent incubation in the absence of MgATP. Similar MgATP sensitivities are observed when MgATP is present only prior to or only during stimulation with Ca2+ with half-maximal stimulation occurring at 0.4-0.5 and 0.6 mM MgATP, respectively. The data indicate that intact cells are primed by intracellular ATP so that immediately upon permeabilization, there is a component of secretion which is independent of medium MgATP. MgATP partially maintains the primed state after permeabilization by acting before Ca2+ in the secretory pathway.
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pubmed:grant | |
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 |
Apr
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
5
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pubmed:volume |
264
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5412-9
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2784433-Adenosine Triphosphate,
pubmed-meshheading:2784433-Adrenal Medulla,
pubmed-meshheading:2784433-Animals,
pubmed-meshheading:2784433-Calcium,
pubmed-meshheading:2784433-Cattle,
pubmed-meshheading:2784433-Cells, Cultured,
pubmed-meshheading:2784433-Exocytosis,
pubmed-meshheading:2784433-Kinetics,
pubmed-meshheading:2784433-Magnesium,
pubmed-meshheading:2784433-Norepinephrine
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pubmed:year |
1989
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pubmed:articleTitle |
MgATP-independent and MgATP-dependent exocytosis. Evidence that MgATP primes adrenal chromaffin cells to undergo exocytosis.
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pubmed:affiliation |
Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109-0626.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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