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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1978-3-29
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pubmed:abstractText |
Isolated villus from human term placenta contains about 167 nmol/g of acetylcholine (ACh). It was incubated in a muscle bath containing Krebs-Ringer bicarbonate buffer (pH 7.2-7.4) at 37 degrees C and ACh released into the medium was analyzed by pyrolysis-gas chromatography. The spontaneous release of ACh into the medium was linear with time and was 35 pmol/g/min. ACh was not released when Ca++ was absent in the medium. Raising the Ca++ concentration in the Krebs-Ringer bicarbonate buffer from 2.34 to 4.64 mM, or adding L-nicotine (58 muM) to the bath, increased the rate of release of ACh to 53 and 47 pmol/min respectively. Nicotine did not exhibit any effect on ACh release in the absence of Ca++ in the medium. Both the rate of the spontaneous release of ACh and the nicotine-induced increase in the release of ACh was decreased by atropine (152 muM). They were not influenced by d-tubocurarine (30 muM). Depolarizing concentrations of potassium (16-63 mM) in the medium increased the rate of release of ACh. Cocaine, a known Ca antagonist, decreased the rate of spontaneous release of ACh as well as nicotine-induced release of ACh. These observations indicate that 1) Ca++ ions in the external medium are required for release of ACh, 2) Ca++ ions in the external medium are required for release of ACh, 2) Ca++ ions act as a link between the stimulation of ACh release and the final release of ACh and 3) The effect of nicotine on placental release of ACh may be classified as a muscarinic type.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Acetylcholine,
http://linkedlifedata.com/resource/pubmed/chemical/Atropine,
http://linkedlifedata.com/resource/pubmed/chemical/Barium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Nicotine,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium,
http://linkedlifedata.com/resource/pubmed/chemical/Tubocurarine
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0022-3565
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
204
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
433-45
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:621673-Acetylcholine,
pubmed-meshheading:621673-Atropine,
pubmed-meshheading:621673-Barium,
pubmed-meshheading:621673-Calcium,
pubmed-meshheading:621673-Chromatography, Gas,
pubmed-meshheading:621673-Drug Interactions,
pubmed-meshheading:621673-Female,
pubmed-meshheading:621673-Humans,
pubmed-meshheading:621673-Magnesium,
pubmed-meshheading:621673-Nicotine,
pubmed-meshheading:621673-Placenta,
pubmed-meshheading:621673-Potassium,
pubmed-meshheading:621673-Pregnancy,
pubmed-meshheading:621673-Tubocurarine
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pubmed:year |
1978
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pubmed:articleTitle |
Human placental cholinergic system: stimulation-secretion coupling for release of acetylcholine from isolated placental villus.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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