Linked Life Data

6972702

Source:http://linkedlifedata.com/resource/pubmed/id/6972702

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1981-8-27
pubmed:abstractText
The relations among alkaline secretion, short-circuit current (Isc), and fluxes of Na+ and Cl- are examined. The Isc (1.15 +/- 0.03 microeq.cm-2.h-1) was significantly greater than the rate of alkaline secretion (1.02 +/- 0.02 microeq.cm-2.h-1). Regression analysis (n = 300) showed a highly significant correlation between alkaline secretion and Isc and indicated a residual Isc of 0.26 microeq.cm-2.h-1. In the absence of HCO3-, there was a residual Isc of 0.25 +/- 0.04 microeq.cm-2.h-1. This residual Isc is accounted for by an observed net Na+ absorption of 0.28 +/- 0.04 microeq.cm-2.h-1. Fluxes of Na+ fail to fit the flux-ratio equation and were not significantly affected by 2 X 10(-6) M ouabain, 5 X 10(-5) M amiloride, or anoxia but were significantly reduced by 2,4,6-triaminopyrimidine. The net Cl- flux was not significantly different from zero. Cl- fluxes conform to the flux-ratio equation and were reduced by anoxia or 2,4,6-triaminopyrimidine but were not affected by 4-acetamido-4'-isothiocynostilbene-2,2'-disulfonic acid (SITS). Anoxia or ouabain significantly inhibited alkaline secretion and Isc without affecting net fluxes of Na+ or Cl-, whereas amiloride or SITS had no effect on any of these parameters. There is no NaCl-coupled transport nor anion exchange, but solute-coupled Na+ absorption is demonstrated. We conclude that alkaline secretion by the duodenum involves a transcellular, energy-requiring, Na+-dependent, ouabain-sensitive, electrogenic mechanism that accounts for at least 80% of the Isc. Net Na+ absorption accounts for the residual Isc. Movements of Cl- are passive, do not contribute to Isc, and are not involved in the mechanism of alkaline secretion. Two hypothetical models of transcellular alkaline secretion are proposed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
240
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G472-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
Alkaline secretion by amphibian duodenum. II. Short-circuit current and Na+ and Cl- fluxes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.