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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2 Pt 2
|
| pubmed:dateCreated |
1990-4-3
|
| pubmed:abstractText |
The influence of pH on sodium-phosphate cotransport was determined in brush-border membrane vesicles (BBMV) isolated from outer cortical and outer medullary tissue of porcine kidneys. Two transport systems are apparent in outer cortical brush-border vesicles, and one process is apparent in outer medullary vesicles at all pH values. The apparent maximum uptake rate (Vmax) of the low-affinity system in outer cortex vesicles decreased from 8.3 +/- 1.7 to 3.2 +/- 0.05 nmol.mg protein-1.min-1 with pH change of 8.0 to 6.0, and the high-affinity process changed from 1.3 +/- 0.2 to 0.1 +/- 0.01 nmol.mg protein-1.min-1. The respective affinity values (Km) also decreased 5.5 +/- 0.9 to 0.6 +/- 0.01 mM and 0.08 +/- 0.005 to 0.01 +/- 0.005 mM, respectively, with acidification. In outer medullary vesicles a decrease in pH diminished the apparent Km, 0.28 +/- 0.03 to 0.02 +/- 0.003 mM, and mean Vmax from 3.0 +/- 0.07 to 0.5 +/- 0.1 nmol.mg protein-1.min-1. The mean KNaD values were 22.1 +/- 4.2 mM in outer cortical vesicles (low-affinity system) and 58.7 +/- 7.2 mM in outer medullary vesicles (high-affinity system) and were not altered by pH, suggesting that H+ does not affect the sodium interactive site. The data suggest that the vesicles prepared from outer cortical and outer medullary tissue possess distinctive sodium-phosphate transporters that are sensitive to external H+ concentrations.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Feb
|
| pubmed:issn |
0002-9513
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
258
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
F356-63
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:2155540-Animals,
pubmed-meshheading:2155540-Biological Transport,
pubmed-meshheading:2155540-Hydrogen-Ion Concentration,
pubmed-meshheading:2155540-Kidney Cortex,
pubmed-meshheading:2155540-Kidney Medulla,
pubmed-meshheading:2155540-Kinetics,
pubmed-meshheading:2155540-Microvilli,
pubmed-meshheading:2155540-Phosphates,
pubmed-meshheading:2155540-Protons,
pubmed-meshheading:2155540-Sodium,
pubmed-meshheading:2155540-Swine
|
| pubmed:year |
1990
|
| pubmed:articleTitle |
Effect of pH on Na(+)-dependent phosphate transport in renal outer cortical and outer medullary BBMV.
|
| pubmed:affiliation |
Department of Medicine, University Hospital, University of British Columbia, Vancouver, Canada.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|