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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1993-9-22
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pubmed:abstractText |
High-resolution microscopy in conjunction with colloidal gold-labeled insulin-like growth factor I (IGF-I) has been used to provide evidence that the IGF-I receptor is first detected in 8-cell-stage mouse embryos, confirming the results of previous reverse transcriptase polymerase chain reaction (RT-PCR) studies. Specificity for the IGF-I receptor was demonstrated by displacement with unlabeled IGF-I and dual-labeling experiments with colloidal gold-labeled or unlabeled insulin. Labeled IGF-I ligand is internalized by means of receptor-mediated endocytosis following its concentration in coated pits, and it can be visualized within cytoplasmic organelles. Immunocytochemical analyses at the blastocyst stage, using gold-labeled antibodies to the receptor, confirmed the expression of IGF-I receptors on all cells of the embryo. Similar studies with antibodies directed against the ligand demonstrated that IGF-I internalized by the embryo in vivo is maternally derived. Approximately 40% of blastocysts showed apical plasma membrane binding of gold-labeled ligand ("responders"), while approximately 60% did not demonstrate binding ("nonresponders"); however, both classes of embryo expressed receptors on basolateral membranes of trophectoderm cells and on the surface of inner masses. Functional studies show that incubating embryos in physiological levels of IGF-I (40 ng/ml) results in increased numbers of cells in the inner cell mass (p < 0.05), but not the trophectoderm, as compared to controls.
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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 |
Jul
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pubmed:issn |
0006-3363
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
49
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1-12
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:8353175-Animals,
pubmed-meshheading:8353175-Blastocyst,
pubmed-meshheading:8353175-Cell Count,
pubmed-meshheading:8353175-Endocytosis,
pubmed-meshheading:8353175-Female,
pubmed-meshheading:8353175-Insulin,
pubmed-meshheading:8353175-Insulin-Like Growth Factor I,
pubmed-meshheading:8353175-Insulin-Like Growth Factor II,
pubmed-meshheading:8353175-Mice,
pubmed-meshheading:8353175-Microscopy, Immunoelectron,
pubmed-meshheading:8353175-Pregnancy,
pubmed-meshheading:8353175-Receptor, IGF Type 1
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pubmed:year |
1993
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pubmed:articleTitle |
Mouse preimplantation embryos exhibit receptor-mediated binding and transcytosis of maternal insulin-like growth factor I.
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pubmed:affiliation |
Department of Pathology and Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia 19104.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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