Linked Life Data

6405628

Source:http://linkedlifedata.com/resource/pubmed/id/6405628

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1983-6-10
pubmed:abstractText
The purpose of this study was to determine and compare pH, PCO2, and fractional bicarbonate delivery in both superficial and juxtamedullary nephrons by microelectrode techniques and microcalorimetry in the rat in vivo in order to define more clearly the role of deeper nephron segments in urinary acidification. Values for pH and total CO2 concentration ([tCO2]) at the bend of Henle's loop (LOH) (7.39 +/- 0.04 units and 20.5 +/- 1.5 mM) were significantly greater and the PCO2 was significantly less (36.6 +/- 1.5 mmHg) than values for these same parameters in the superficial late proximal tubule (LPT) (6.78 +/- 0.03 units, 8.1 +/- 1.2 mM, and 63.2 +/- 1.0 mmHg, P less than 0.001). The fraction of filtered bicarbonate delivered to the LPT and LOH did not differ, however (12.2 +/- 2.5 vs. 9.0 +/- 0.8%). The pH and PCO2 values in the late distal tubule (6.59 +/- 0.04 units and 64.0 +/- 1.3 mmHg) were significantly greater than at the base (6.24 +/- 0.07 units and 34.5 +/- 1.5 mmHg) and tip (6.12 +/- 0.03 units and 35.2 +/- 1.2 mmHg) of the papillary collecting duct. The [tCO2] in the LOH and an adjacent vasa recta was compared and did not differ significantly (20.5 +/- 1.5 vs. 21.2 +/- 1.3 mM, P greater than 0.05). In summary, we have demonstrated significant alkalinization of tubule fluid in the deep LOH as a result of water abstraction and CO2 diffusion from the nephron. Our results suggest that a spontaneous disequilibrium pH may not exist in the LOH. Furthermore, similar values for [tCO2] in vasa recta and the LOH suggest that passive HCO-3 reabsorption in the thin ascending limb of Henle would be unlikely and does not contribute to the "loop" component of bicarbonate reabsorption.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
244
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F497-503
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Comparison of acidification parameters in superficial and deep nephrons of the rat.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.