| Effects of dietary magnesium on sodium-potassium pump action in the heart of rats. | |
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MedLine Citation:
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PMID: 2826728 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Sprague-Dawley rats were fed a basal AIN-76 diet containing 80, 200, 350, 500 or 650 mg of magnesium per kilogram of diet for 6 wk. Ventricular slices, as well as microsomal fractions, were prepared from the hearts and were used to determine sodium-potassium pump activity. Sodium-potassium pump activity was assessed in the microsomal membranes by determining the ouabain-inhibitable Na+, K+-ATPase activity and [3H]ouabain binding, and in the ventricular slices, by determining ouabain-sensitive 86Rb uptake under K+-free conditions. The ATPase activity increased with increasing dietary magnesium, so that in the hearts of those animals that were fed 500 and 650 mg of magnesium/kg diet, it was significantly greater than the activity in the hearts of the animals fed 80 and 200 mg/kg diet. Similarly, 86Rb uptake by heart slices from rats fed 500 and 650 mg of magnesium/kg diet was significantly greater than the uptake by heart slices from animals fed 80 and 200 mg/kg diet. [3H]Ouabain binding did not change with increasing dietary magnesium. Thus, magnesium deficiency appears to have no effect on the number of sodium-potassium pump sites, but does decrease the activity of the pump. It is suggested that this leads to an increase in intracellular Na+, resulting in a change in the membrane potential, and may contribute to the arrhythmias associated with magnesium deficiency. |
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Authors:
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P W Fischer; A Giroux |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The Journal of nutrition Volume: 117 ISSN: 0022-3166 ISO Abbreviation: J. Nutr. Publication Date: 1987 Dec |
Date Detail:
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Created Date: 1988-02-17 Completed Date: 1988-02-17 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0404243 Medline TA: J Nutr Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 2091-5 Citation Subset: IM |
Affiliation:
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Nutrition Research Division, Health and Welfare Canada, Ottawa, Ontario. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Diet Magnesium / pharmacology* Male Methods Microsomes / analysis Myocardium / metabolism* Potassium / metabolism* Rats Rats, Inbred Strains Rubidium Radioisotopes / diagnostic use Sodium / metabolism* Sodium-Potassium-Exchanging ATPase / analysis |
| Chemical | |
Reg. No./Substance:
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0/Rubidium Radioisotopes; 7439-95-4/Magnesium; 7440-09-7/Potassium; 7440-23-5/Sodium; 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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