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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1983-4-7
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pubmed:abstractText |
Hepatocyte phosphatidylinositol 4,5-bisphosphate (4,5-P2), phosphatidylinositol 4-phosphate (4-P), and phosphatidylinositol were labeled with 3H when rats were injected intraperitoneally with 200 microCi of [2-3H] myo-inositol 18 h previously. Phosphatidylinositol 4,5-P2 and phosphatidylinositol 4-P accounted for 0.84 +/- 0.06 and 7.48 +/- 0.36%, respectively, of the total [3H] myo-inositol containing phospholipids. The breakdown of phosphatidylinositol 4,5-P2 was stimulated transiently (maximum effect seen at 15 s) and in a Ca2+-dependent manner by 10(-8) M vasopressin. Phosphatidylinositol 4-P breakdown was enhanced to a smaller, but longer, extent by vasopressin, whereas no changes in phosphatidylinositol were detected up to 120 s. Subcellular fractionation studies also showed no preferential breakdown of phosphatidylinositol in plasma membranes at 5-20 min. Only doses of vasopressin (10(-8) and 10(-7) M) in excess of those producing maximum effects on phosphorylase activation and Ca2+ efflux (10(-9) M) were effective at stimulating phosphatidylinositol 4,5-P2 breakdown. It is concluded that phosphatidylinositol 4,5-P2 breakdown induced by vasopressin in rat hepatocytes is not responsible for the mobilization of Ca2+ which leads to the activation of phosphorylase. On the contrary, it is Ca2+-dependent and appears to require the occupation of more receptors than are required for Ca2+ mobilization and phosphorylase activation.
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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 |
Mar
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
10
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pubmed:volume |
258
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2770-3
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:6298203-Animals,
pubmed-meshheading:6298203-Hydrolysis,
pubmed-meshheading:6298203-Inositol,
pubmed-meshheading:6298203-Kinetics,
pubmed-meshheading:6298203-Liver,
pubmed-meshheading:6298203-Male,
pubmed-meshheading:6298203-Phosphatidylinositol 4,5-Diphosphate,
pubmed-meshheading:6298203-Phosphatidylinositols,
pubmed-meshheading:6298203-Rats,
pubmed-meshheading:6298203-Rats, Inbred Strains,
pubmed-meshheading:6298203-Subcellular Fractions,
pubmed-meshheading:6298203-Vasopressins
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pubmed:year |
1983
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pubmed:articleTitle |
Stimulation of phosphatidylinositol 4,5-bisphosphate hydrolysis in hepatocytes by vasopressin.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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