Linked Life Data

6458704

Source:http://linkedlifedata.com/resource/pubmed/id/6458704

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1982-2-12
pubmed:abstractText
The acidification of kinetics of artificial solutions containing buffers of different permeancy were studied in rat proximal tubules by means of stationary microperfusion techniques. Luminal pH changes were measured by antimony microelectrodes and used to calculate net rates of acidification and the approach to steady-state pH levels. For most buffer species, tracer efflux out of the lumen was compared with changes in buffer concentration as derived from calculations based on the Henderson Hasselbalch equation. Steady-state luminal pH was similar for most buffer systems studied. However, secretory hydrogen ion fluxes into the lumen were significantly higher for permeant than for less permeant buffers. The most likely explanation is that permeant buffers behave as "open" systems maintaining constant low diffusible acid levels in the lumen, whereas impermeant buffers behave as "closed" systems in which non-ionized acid levels are maintained at higher levels. A behavior consistent with this thesis was directly demonstrated for glycodiazine and, to a lesser degree, for DMO. In contrast, phosphate and creatinine behave like buffers in a "closed" system. Characteristics of proximal tubular acidification, of buffer reabsorption, and the effect thereupon of carbonic anhydrase inhibitors are satisfactorily explained by an essential role of (1) hydrogen ion secretion, (2) pK differences, and (3) different permeance of the non-ionized buffer species. However, specific transport mechanisms may, in addition, also contribute to differences in transepithelial buffer movement.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0022-2631
pubmed:author
pubmed:issnType
Print
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13-24
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Role of luminal buffers in renal tubular acidification.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't