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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1997-2-27
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pubmed:abstractText |
1. Adrenaline (5 microM) stimulated a K+ secretory current by 2.2 mu equiv h-1 cm-2 in isolated guinea-pig distal colonic epithelium. This secretory activity was inhibited entirely by addition of the loop diuretic bumetanide to the serosal solution. On-going K+ uptake via the absorptive pathway was unaltered by these changes. 2. Prostaglandin E2 (PGE2, 2 microM) stimulated electrogenic K+ secretion and Cl- secretion by 3.0 and 3.6 mu equiv h-1 cm-2, respectively. Serosal addition of bumetanide completely inhibited this K+ secretion but blocked only approximately 70% of Cl- secretion. The bumetanide-insensitive Cl- secretory current was dependent on the presence of Cl- and HCO3- in the bathing solutions. 3. Stimulation of electrogenic K+ secretion by PGE2 occurred with a half-maximal concentration of 4 nM, an affinity approximately 300 times higher than that for stimulation of Cl- secretion by PGE2. 4. Forskolin (10 microM) stimulated Cl- secretion by 4.9 mu equiv h-1 cm-2. The apparent K+ secretory rate was increased by only 1.5 mu equiv h-1 cm-2. A bumetanide-insensitive short-circuit current (ISC) was apparent and of the same size as that stimulated by PGE2. 5. Addition of the Ca2+ ionophore A23187 (10 microM), in the presence of indomethacin (1 microM) to reduce prostaglandin production, inhibited the K+ absorptive pathway by 40% and concurrently stimulated a small rate of electrogenic K+ secretion. 6. Active K+ absorption was inhibited by the addition of ouabain, omeprazole or SCH28080 to the mucosal solution. Both omeprazole and SCH28080 also stimulated a small negative ISC, consistent with electrogenic K+ secretion. 7. Association of K+ absorption, K+ secretion and Cl- secretion is indicated by similarities in transport mechanism and by secretagogue regulation. In particular, maximal rates of K+ secretory current require uptake via apical membrane K+ pumps. Such interrelations support a common cellular locus for these ion transport pathways.
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pubmed:grant |
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-1587404,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-1616006,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-1837421,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2139761,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2143781,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2170221,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2410537,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2426961,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2580086,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2735416,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2911583,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2921323,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-2981482,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3021724,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3031995,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3039216,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3303961,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3650023,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-3970198,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-6331183,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-6439051,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-6703045,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-6742138,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-7560093,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-7617439,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-7864124,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-8141270,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-8214063,
http://linkedlifedata.com/resource/pubmed/commentcorrection/8782111-8238299
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
0022-3751
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
493 ( Pt 2)
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
485-502
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:8782111-Adenosine Triphosphatases,
pubmed-meshheading:8782111-Adrenergic Agents,
pubmed-meshheading:8782111-Animals,
pubmed-meshheading:8782111-Biological Transport, Active,
pubmed-meshheading:8782111-Chloride Channels,
pubmed-meshheading:8782111-Colon,
pubmed-meshheading:8782111-Cyclooxygenase Inhibitors,
pubmed-meshheading:8782111-Dinoprostone,
pubmed-meshheading:8782111-Electrophysiology,
pubmed-meshheading:8782111-Epinephrine,
pubmed-meshheading:8782111-Guinea Pigs,
pubmed-meshheading:8782111-Indomethacin,
pubmed-meshheading:8782111-Intestinal Mucosa,
pubmed-meshheading:8782111-Male,
pubmed-meshheading:8782111-Models, Biological,
pubmed-meshheading:8782111-Patch-Clamp Techniques,
pubmed-meshheading:8782111-Potassium,
pubmed-meshheading:8782111-Potassium Channels
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pubmed:year |
1996
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pubmed:articleTitle |
Active potassium transport across guinea-pig distal colon: action of secretagogues.
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pubmed:affiliation |
Federal Research Centre for Nutrition, Institute of Nutritional Physiology, Eggenstein-Leopoldshafen, Germany.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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