| Ammonia and bicarbonate transport by rat cortical collecting ducts perfused in vitro. | |
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MedLine Citation:
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PMID: 3934984 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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We measured bicarbonate and ammonia transport by isolated perfused cortical collecting ducts from deoxycorticosterone-treated rats. With no ammonia in the perfusate and bath solutions, the collecting ducts secreted bicarbonate. The bicarbonate secretion was prevented when the rats were given 40 mM NH4Cl to drink. When 4 mM total ammonia was added to the perfusate and bath, the collecting ducts secreted ammonia and the direction of bicarbonate transport reversed toward absorption. Under those conditions the collected total ammonia concentration exceeded the value predicted by the diffusion-trapping model, assuming pH equilibrium. However, when carbonic anhydrase was added to the perfusate (to assure pH equilibrium), the collected total ammonia concentration decreased to the level predicted by the diffusion-trapping model. We conclude that rat cortical collecting ducts can secrete bicarbonate at substantial rates; the rate of bicarbonate secretion is modified by changes in the acid-base intake of the rats; ammonia secretion occurs by simple nonionic diffusion in this segment; the ammonia secretion is enhanced by the presence of acidic pH disequilibrium in the lumen; and ammonia in the perfusion and bath solutions inhibits bicarbonate secretion by rat cortical collecting ducts, a response that may be important for the regulation of renal bicarbonate excretion. |
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Authors:
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M A Knepper; D W Good; M B Burg |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: The American journal of physiology Volume: 249 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1985 Dec |
Date Detail:
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Created Date: 1986-01-23 Completed Date: 1986-01-23 Revised Date: 2003-11-14 |
Medline Journal Info:
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Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: F870-7 Citation Subset: IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Ammonia
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metabolism* Ammonium Chloride / pharmacology Animals Bicarbonates / metabolism* Biological Transport, Active / drug effects Carbon Dioxide / metabolism Carbonic Anhydrases / metabolism Desoxycorticosterone / pharmacology Diet Kidney Cortex / drug effects, metabolism* Kidney Tubules / metabolism* Kidney Tubules, Collecting / drug effects, metabolism* Male Perfusion Rats Rats, Inbred Strains |
| Chemical | |
Reg. No./Substance:
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0/Bicarbonates; 12125-02-9/Ammonium Chloride; 124-38-9/Carbon Dioxide; 64-85-7/Desoxycorticosterone; 7664-41-7/Ammonia; EC 4.2.1.1/Carbonic Anhydrases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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