| Insulin stimulation of human adipocytes activates the kinase of only a fraction of the insulin receptors. | |
| | |
MedLine Citation:
|
PMID: 9142877 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The degree of insulin receptor kinase activation by in situ stimulation was studied in isolated human adipocytes. Although maximal in situ stimulation increased the kinase activity approximately 10-fold, this activity could again be doubled by subsequent activation in a cell-free system. To investigate how in situ stimulation resulted in incomplete activation, receptors binding or not binding to anti-phosphotyrosine antibody (alpha-PY) were studied separately. Even after maximal insulin stimulation of the cells, approximately 50% of the receptors did not bind to alpha-PY and had low kinase activity. In the cell-free system, however, these receptors reached activity levels similar to the other receptors, suggesting that they were intact and that factors in their cellular environment had prevented their activation. The activity of the alpha-PY-binding receptors could only be slightly increased in the cell-free system, suggesting that almost complete activation had been attained in situ. In situ stimulation with increasing insulin concentrations increased the number of activated receptors rather than their individual activity. We conclude that factors in the in situ environment prevent insulin activation of approximately 50% of the insulin receptors in human adipocytes and might therefore be important regulators of insulin signaling. |
| | |
Authors:
|
H H Klein; B Kowalewski; M Drenckhan; H L Fehm |
Related Documents
:
|
2650737 - Receptor cross-linking restores an insulin metabolic effect altered by mutation on tyro... 12091387 - The long and short isoforms of ret function as independent signaling complexes. 16778057 - Neuronal pathway from the liver modulates energy expenditure and systemic insulin sensi... 17189427 - Essential role of insulin and insulin-like growth factor 1 receptor signaling in cardia... 11742137 - The 5-ht(1a) receptor knockout mouse and anxiety. 14660627 - Cross-talk and co-trafficking between rho1/gaba receptors and atp-gated channels. |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The American journal of physiology Volume: 272 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1997 Apr |
Date Detail:
|
Created Date: 1997-06-06 Completed Date: 1997-06-06 Revised Date: 2009-11-19 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: E576-83 Citation Subset: IM |
Affiliation:
|
Department of Internal Medicine, Medical University of Lübeck, Germany. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adipocytes
/
enzymology*,
immunology Animals Antibodies / immunology Cell-Free System / metabolism Enzyme Activation Humans Insulin / pharmacology* Phosphorylation Phosphotyrosine / immunology Receptor, Insulin / immunology, metabolism* Solubility Swine Tyrosine / metabolism |
| Chemical | |
Reg. No./Substance:
|
0/Antibodies; 11061-68-0/Insulin; 21820-51-9/Phosphotyrosine; 55520-40-6/Tyrosine; EC 2.7.10.1/Receptor, Insulin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Brain of the conscious dog is sensitive to physiological changes in circulating insulin.
Next Document: Influence of protein intake on whole body and splanchnic leucine kinetics in humans.