| Copper stimulation of LHRH release from median eminence explants. III. A process dependent on extracellular sodium. | |
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MedLine Citation:
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PMID: 3027598 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Copper, complexed to histidine (CuHis), stimulates LHRH release from explants of the median eminence area (MEA). To gain further understanding of the mechanism of copper action, in this study, we assessed the Na+ and energy requirements for CuHis stimulation of LHRH release. MEA explants, obtained from adult male rats, were incubated at 37 degrees C for 15 min with 100 microM CuHis and then for 45 min in CuHis-free medium (Krebs-Ringer-phosphate buffer, pH 7.4). LHRH released into the medium was evaluated by RIA. When the incubation buffer contained 143 mM Na+, CuHis stimulated the release of LHRH from a basal level of 17.2 +/- 1.26 (mean +/- SEM, n = 7) to 74.5 +/- 6.2 pg/60 min per MEA. When [Na+] was reduced to 16 mM Na+ (by substituting with Li+), CuHis-stimulated LHRH release was inhibited by 80% (p less than 0.001); indicating a requirement for Na+. In addition, we found that CuHis-stimulated LHRH release was a saturable function of Na+ concentration; saturation achieved with about 100 mM Na+. To assess the requirement for Na+ transport, we evaluated the effect of 1 mM ouabain, 10 microM tetrodotoxin (TTX), or 100 microM amiloride on CuHis stimulation of LHRH release. Ouabain inhibited CuHis stimulation of LHRH release by 80%, whereas TTX and amiloride were ineffective. In addition, we observed that CuHis did not stimulate LHRH release when incubation was carried out at 4 degrees C or at 37 degrees C in the presence of 5 mM KCN.(ABSTRACT TRUNCATED AT 250 WORDS) |
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Authors:
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M Colombani-Vidal; A Barnea |
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Publication Detail:
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Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: Neuroendocrinology Volume: 44 ISSN: 0028-3835 ISO Abbreviation: Neuroendocrinology Publication Date: 1986 |
Date Detail:
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Created Date: 1987-03-05 Completed Date: 1987-03-05 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0035665 Medline TA: Neuroendocrinology Country: SWITZERLAND |
Other Details:
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Languages: eng Pagination: 283-91 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Cell Membrane Permeability Copper / pharmacology* Culture Techniques Energy Metabolism Gonadotropin-Releasing Hormone / secretion* Male Median Eminence / metabolism* Rats Sodium / physiology* Sodium-Potassium-Exchanging ATPase / metabolism Stimulation, Chemical |
| Grant Support | |
ID/Acronym/Agency:
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AM25692/AM/NIADDK NIH HHS |
| Chemical | |
Reg. No./Substance:
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33515-09-2/Gonadotropin-Releasing Hormone; 7440-23-5/Sodium; 7440-50-8/Copper; EC 3.6.3.9/Sodium-Potassium-Exchanging ATPase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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