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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5 Pt 1
|
| pubmed:dateCreated |
1984-6-20
|
| pubmed:abstractText |
To characterize and contrast the active potassium absorptive and secretory processes present in the rat colon, unidirectional 42K fluxes were performed under short-circuit conditions across isolated distal (D) and proximal (P) colonic mucosa of control rats and animals with hyperaldosteronism due to sodium depletion (aldosterone group). In the control D colon there was net potassium absorption (+0.51 +/- 0.07 mueq X h-1 X cm-2). The absorptive process appears electroneutral because net potassium flux ( JK net ) was unchanged in sodium-free Ringer solution (+0.76 +/- 0.12 mueq X h-1 X cm-2), whereas short-circuit current (Isc) was reduced to zero, and in chloride-free Ringer solution. In P colon of controls, net potassium secretion was -0.19 +/- 0.02 mueq X h-1 X cm-2 and was abolished by removal of sodium but not by removal of chloride. In both P and D colon aldosterone produced active potassium secretion (-0.39 +/- 0.06 mueq X h-1 X cm-2, P less than 0.001, and -0.90 +/- 0.07 mueq X h-1 X cm-2, P less than 0.001, respectively) that was sodium and chloride dependent. Although mucosal amiloride in D colon of aldosterone animals reduced net sodium flux to zero and reversed Isc from 4.1 +/- 0.6 to -1.1 +/- 0.1 mueq X h-1 X cm-2, net potassium secretion was not affected. Thus, in the presence of amiloride, Isc is accounted for by JK net (-0.93 +/- 0.12 mueq X h-1 X cm-2). These data indicate that 1) the active potassium absorptive process is electroneutral and could be explained by a potassium-proton exchange, and 2) the potassium secretory process is stimulated by aldosterone, is not inhibited by amiloride, and probably is electrogenic.
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| 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 |
246
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
G611-7
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:6720956-Aldosterone,
pubmed-meshheading:6720956-Amiloride,
pubmed-meshheading:6720956-Animals,
pubmed-meshheading:6720956-Biological Transport, Active,
pubmed-meshheading:6720956-Colon,
pubmed-meshheading:6720956-Intestinal Absorption,
pubmed-meshheading:6720956-Intestinal Mucosa,
pubmed-meshheading:6720956-Kinetics,
pubmed-meshheading:6720956-Male,
pubmed-meshheading:6720956-Potassium,
pubmed-meshheading:6720956-Potassium Radioisotopes,
pubmed-meshheading:6720956-Rats,
pubmed-meshheading:6720956-Rats, Inbred Strains
|
| pubmed:year |
1984
|
| pubmed:articleTitle |
Mechanism of active potassium absorption and secretion in the rat colon.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|