| Prolonged administration in vivo of alpha and beta adrenergic agonists decreases insulin binding to rat myocardial membranes in vitro by different mechanisms. | |
MedLine Citation:
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PMID: 1675412 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Male Sprague Dawley rats were continuously treated in vivo for 6, 12 and 20 hours with a combination of an alpha- (beta-) adrenoreceptor agonist and a beta- (alpha-) adrenoreceptor antagonist in subcutaneously implanted depot tablets. Crude membranes prepared from myocardial cells exhibited a decreased maximum binding of [125I]-insulin after 20 hours irrespective of the treatment applied. Scatchard and non-linear regression analysis of the displacement curves assuming two non-cooperative binding sites revealed a downregulation of the high affinity receptors for about 85% and a concomitant 2.5-fold increased receptor affinity under beta-adrenergic influence. In contrast, alpha-adrenergic treatment did not affect the receptor number but decreased the high affinity by 70%. The low affinity binding sites were virtually unaffected by the different treatments. The phospholipid and cholesterol contents of the membranes were not significantly altered. The phospholipid/cholesterol ratios after 12 and 20 hours of alpha-adrenergic treatment, however, were decreased. We suggest that the decreased binding activity of insulin receptors on rat myocardial membranes after continuous in vivo treatment with alpha- and beta- adrenergic agonists is mediated by different mechanisms. |
Authors:
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G Desoye; U Ertl-Stockinger; S Porta |
Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Life sciences Volume: 48 ISSN: 0024-3205 ISO Abbreviation: Life Sci. Publication Date: 1991 |
Date Detail:
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Created Date: 1991-07-12 Completed Date: 1991-07-12 Revised Date: 2009-11-19 |
Medline Journal Info:
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Nlm Unique ID: 0375521 Medline TA: Life Sci Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 2249-58 Citation Subset: IM |
Affiliation:
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Department of Obstetrics and Gynecology, University of Graz, Austria. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adrenergic alpha-Agonists
/
pharmacology* Adrenergic beta-Agonists / pharmacology* Animals Blood Glucose / metabolism Drug Administration Schedule Drug Implants Heart / drug effects Kinetics Male Myocardium / metabolism* Rats Rats, Inbred Strains Receptor, Insulin / drug effects* |
| Chemical | |
Reg. No./Substance:
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0/Adrenergic alpha-Agonists; 0/Adrenergic beta-Agonists; 0/Blood Glucose; 0/Drug Implants; EC 2.7.10.1/Receptor, Insulin |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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