| Renal tubular transport of folic acid and methotrexate in the monkey. | |
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MedLine Citation:
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PMID: 7081435 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The renal excretion of folic acid and methotrexate (MTX) was investigated in pentobarbital-anesthetized cynomolgus, rhesus, and AFrican green monkeys by standard clearance and stop-flow techniques. The renal clearance of folic acid was below inulin clearance at all plasma concentrations studied; the (U/P)folic/(U/P)In ratio increased from 0.26 at a concentration of 0.03 mM to a plateau value of 0.9 at concentrations above 0.2 mM, indicating net reabsorption by a saturable system. In stop-flow experiments, base-line (U/P)folic/(U/P)In ratios during free-flow periods were below 1.0, but increased by twofold in stop-flow samples derived from the proximal tubule, indicating net secretion during stopped flow. The stop-flow pattern of MTX excretion was similar, except the base-line flow pattern of MTX excretion was similar, except the base-line (U/P)MTX/(U/P)In ratio exceeded 1.0, indicating net secretion during both free-flow and stopped-flow periods. Secretion of both compounds was inhibited by p-aminohippuric acid and other organic acids but not by L-glutamic acid. It is concluded that folic acid is transported bidirectionally, while evidence was obtained only for secretion of MTX. |
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Authors:
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W M Williams; K C Huang |
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Publication Detail:
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Type: Comparative Study; 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 American journal of physiology Volume: 242 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1982 May |
Date Detail:
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Created Date: 1982-07-08 Completed Date: 1982-07-08 Revised Date: 2007-11-14 |
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: F484-90 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 Biological Transport Cercopithecus aethiops Folic Acid / metabolism* Homeostasis Kidney Tubules / metabolism* Kidney Tubules, Proximal / metabolism Macaca fascicularis Macaca mulatta Metabolic Clearance Rate Methotrexate / metabolism* Proteins / metabolism |
| Grant Support | |
ID/Acronym/Agency:
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CA25252-02/CA/NCI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Proteins; 59-05-2/Methotrexate; 59-30-3/Folic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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