Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
3 Pt 2
|
| pubmed:dateCreated |
1991-10-4
|
| pubmed:abstractText |
The renal proximal tubule is responsible for the active elimination of organic cations. Studies in brush-border membrane vesicles (BBMV) suggest that active organic cation transport is mediated by an organic cation-proton antiporter. The goals of this study were to determine whether this transporter is expressed in human kidney and to elucidate its characteristics. Transport of the organic cations N1-[3H]methylnicotinamide (NMN) and [14C]tetraethylammonium (TEA) was determined by rapid filtration in BBMV of donor human kidneys. The uptake of NMN and TEA was driven against a concentration gradient by an outwardly directed proton gradient. NMN uptake was inhibited by the organic cations TEA, NMN, quinine, and cimetidine, but was not affected by p-aminohippuric acid, cephalexin, and polyamines. The electroneutral transport of NMN was characterized by a Km of 0.44 +/- 0.07 mM and a Vmax of 24.4 +/- 15.2 pmol.mg protein-1.s-1. The rate of proton efflux from BBMV increased in the presence of an inwardly directed TEA gradient. Preloading BBMV with NMN or TEA trans-stimulated the initial rate of uptake of TEA. Therefore the human proximal tubule expresses an organic cation-proton antiporter in the brush-border membrane. The antiporter is similar to that described in other mammalian species but shows some differences in its transport characteristics.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Cations,
http://linkedlifedata.com/resource/pubmed/chemical/Glucose,
http://linkedlifedata.com/resource/pubmed/chemical/N(1)-methylnicotinamide,
http://linkedlifedata.com/resource/pubmed/chemical/Niacinamide,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium Compounds
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Sep
|
| pubmed:issn |
0002-9513
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
261
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
F443-51
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1832266-Adult,
pubmed-meshheading:1832266-Biological Transport,
pubmed-meshheading:1832266-Cations,
pubmed-meshheading:1832266-Child,
pubmed-meshheading:1832266-Female,
pubmed-meshheading:1832266-Glucose,
pubmed-meshheading:1832266-Humans,
pubmed-meshheading:1832266-Hydrogen-Ion Concentration,
pubmed-meshheading:1832266-Kidney,
pubmed-meshheading:1832266-Kinetics,
pubmed-meshheading:1832266-Male,
pubmed-meshheading:1832266-Microvilli,
pubmed-meshheading:1832266-Middle Aged,
pubmed-meshheading:1832266-Niacinamide,
pubmed-meshheading:1832266-Regression Analysis,
pubmed-meshheading:1832266-Spectrometry, Fluorescence,
pubmed-meshheading:1832266-Tetraethylammonium,
pubmed-meshheading:1832266-Tetraethylammonium Compounds
|
| pubmed:year |
1991
|
| pubmed:articleTitle |
Organic cation transport in human renal brush-border membrane vesicles.
|
| pubmed:affiliation |
School of Pharmacy, University of California, San Francisco 94143.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|