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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1984-10-25
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pubmed:abstractText |
During progesterone-stimulated maturation of defolliculated full-grown Xenopus oocytes, the activities of the transport systems for L-alanine, thymidine, chloride, phosphate, and alkali ions decrease. Differences of the extent and time course of these changes suggest that they are controlled by at least partially independent mechanisms. A closer investigation of the Na-K ATPase has shown that in unstimulated oocytes, ouabain produces maximal inhibition when 8-12 X 10(9) molecules are bound per cell. This number is bound during the first phase of a diphasic uptake process. Since this phase can be suppressed by increasing the concentration of external K+ to 45 mmol/liter or more, it is concluded that it refers to binding to the Na-K pump in the plasma membrane. Ouabain bound prior to progesterone-induced germinal vesicle breakdown (GVBD) remains bound after the breakdown, although the Na-K pump loses the capacity to bind ouabain after GVBD in oocytes that had not been exposed to ouabain preceding GVBD. In the presence of Mg++ membranes isolated before regulatory inhibition of pumping and ouabain binding show a Na+-dependent incorporation of 32P from gamma-[32P]-ATP that can be reversed by the addition of K+. The phosphorylation site migrates on LiDS-polyacrylamide gel electropherograms at about 98,000 daltons and can be identified as a Commassie blue-stainable band.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:issn |
0022-2631
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
79
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
|
pubmed:pagination |
203-10
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pubmed:dateRevised |
2007-11-15
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pubmed:meshHeading |
pubmed-meshheading:6088774-Animals,
pubmed-meshheading:6088774-Cell Membrane,
pubmed-meshheading:6088774-Female,
pubmed-meshheading:6088774-Oocytes,
pubmed-meshheading:6088774-Ouabain,
pubmed-meshheading:6088774-Receptors, Drug,
pubmed-meshheading:6088774-Sodium-Potassium-Exchanging ATPase,
pubmed-meshheading:6088774-Xenopus
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pubmed:year |
1984
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pubmed:articleTitle |
Regulatory changes of membrane transport and ouabain binding during progesterone-induced maturation of Xenopus oocytes.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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