| Urinary concentration in the papillary collecting duct of the rat. Role of the ureter. | |
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MedLine Citation:
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PMID: 7054236 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Urine was observed to flow intermittently in the collecting ducts of the extrarenal papilla of antidiuretic rats. The purpose of this investigation was to test Reinking and Schmidt-Nielsen's hypothesis that intermittent flow plays an important role in the production of maximally concentrated urine. Samples of collecting duct fluid were obtained from the base and tip of the papilla by micropuncture through the intact ureter. Fluid osmolality rose sharply from base, 894+/-120 mosmol/kg H(2)O(-1) (mean+/-SE), to tip, 1,667+/-114 (P<0.001), a distance of only 2 mm, and was due exclusively to reabsorption of water. After excision of the ureter, which abolished intermittent flow, osmolality fell modestly at the base to 723+/-82 mosmol/kg H(2)O(-1) (P < 0.02), but strikingly at the tip to 1,012+/-103 (P < 0.001). The pelvic ureter was paralyzed by topical verapamil and dimethylsulfoxide, which abolished intermittent flow. Osmolality of urine at the tip was not changed (1,959+/-184 mosmol/kg H(2)O(-1) before, vs. 1,957+/-126 after paralysis). The ureter was severed just beyond the papillary tip, a maneuver which preserved intermittent flow but abolished urinary reflux over the papilla. Urinary osmolality fell from 1,876+/-134 mosmol/kg H(2)O(-1) to 1,284+/-115 (P < 0.005). These findings demonstrate that when the ureter is intact, over half of the increase in urinary osmolality above isotonicity occurs in the terminal one-fourth of the medullary collecting duct and is due exclusively to water reabsorption (no net solute addition). It is the continuity of the ureter, rather than intermittent flow due to ureteral peristalsis, which is essential for the formation of a maximally concentrated urine. |
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Authors:
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R E Oliver; D R Roy; R L Jamison |
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Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The Journal of clinical investigation Volume: 69 ISSN: 0021-9738 ISO Abbreviation: J. Clin. Invest. Publication Date: 1982 Jan |
Date Detail:
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Created Date: 1982-03-22 Completed Date: 1982-03-22 Revised Date: 2009-11-18 |
Medline Journal Info:
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Nlm Unique ID: 7802877 Medline TA: J Clin Invest Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 157-64 Citation Subset: AIM; IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Female Kidney Concentrating Ability* Kidney Tubules / physiology* Kidney Tubules, Collecting / physiology* Male Paralysis Rats Rheology Ureter / drug effects, physiology* Verapamil / pharmacology |
| Grant Support | |
ID/Acronym/Agency:
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5R01 AM 18077/AM/NIADDK NIH HHS |
| Chemical | |
Reg. No./Substance:
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52-53-9/Verapamil |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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