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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1983-4-15
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pubmed:abstractText |
An LH sensitive adenylate cyclase from a tumour Leydig cell has been investigated. The plasma membranes, prepared by a 2 phase (dextran-polyethylene glycol) centrifugation method were found to have the following properties: In the presence of LH plus p(NH)ppG (guanosine 5'-beta, gamma-imido triphosphate) or fluoride ions, maximum adenylate cyclase activity was obtained in the plasma membranes with 4 to 6 mM Mg2+ plus 0.33 to 2 mM ATP. LH alone stimulated adenylate cyclase activity 2-fold when compared with basal activity and the time course of cyclic AMP production was linear up to 45 min. With GTP (10(-5)M) and GTP plus LH, adenylate cyclase activity was increased 3 and 6-fold, respectively, for up to 20 min and thereafter declined. In contrast p(NH)ppG (10(-5)M) and p(NH)ppG plus LH increased adenylate cyclase activity 7 and 14-fold which was maintained for at least 45 min. Fluoride ions increased the enzyme activity linearly over 45 min approx 18-fold. When GTP or p(NH)ppG were added alone there was a lag time of activation of approximately 10 min which was abolished by the addition of LH. GTP but not p(NH)ppG at concentrations greater than 10(-4) inhibited basal and LH stimulated adenylate cyclase when compared with 10(-5)M GTP. The tumour Leydig cell adenylate cyclase is thus essentially similar to other hormone sensitive somatic cells. The present study makes it feasible to prepare plasma membranes by a simple method from large quantities of pure Leydig cells.
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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/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Adenylate Cyclase,
http://linkedlifedata.com/resource/pubmed/chemical/Guanylyl Imidodiphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Luteinizing Hormone,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium Fluoride
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0105-6263
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
5
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
557-69
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:7160920-Adenosine Triphosphate,
pubmed-meshheading:7160920-Adenylate Cyclase,
pubmed-meshheading:7160920-Animals,
pubmed-meshheading:7160920-Cell Fractionation,
pubmed-meshheading:7160920-Cell Membrane,
pubmed-meshheading:7160920-Guanylyl Imidodiphosphate,
pubmed-meshheading:7160920-Kinetics,
pubmed-meshheading:7160920-Leydig Cell Tumor,
pubmed-meshheading:7160920-Luteinizing Hormone,
pubmed-meshheading:7160920-Magnesium,
pubmed-meshheading:7160920-Male,
pubmed-meshheading:7160920-Sodium Fluoride,
pubmed-meshheading:7160920-Testicular Neoplasms
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pubmed:year |
1982
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pubmed:articleTitle |
Isolation and characterization of plasma membranes containing LH sensitive adenylate cyclase from a Leydig cell tumour.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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