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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
6 Pt 1
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pubmed:dateCreated |
1990-2-12
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pubmed:abstractText |
The biochemical and Ca2+ transport pathways involved in generating the hormone-evoked Ca2+ signal are reported to be influenced by pH. The present study was designed to determine the effect of extracellular pH (pHo) and intracellular pH (pHi) on hormone-stimulated Ca2+ transport. We used rat pancreatic acini and measured free cytosolic Ca2+ concentration ([Ca2+]i) with fura-2, pHi with 2,7-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF), and Ca2+ fluxes with 45Ca2+. In the presence of external Ca2+, increasing pHo increased steady-state [Ca2+]i during sustained agonist stimulation; in the absence of external Ca2+, this increase in [Ca2+]i did not occur. The addition of an antagonist or blocking plasma membrane Ca2+ influx with La3+ in stimulated cells suspended at pHo 8.2 resulted in a reduction in [Ca2+]i. Increasing pHo increased the rate and extent of 45Ca2+ uptake into stimulated cells and the rate and extent of Ca2+ reloading of intracellular stores. The increased Ca2+ content of the intracellular stores with increased pHo indicated that at physiological pHo and pHi the agonist-mobilizable internal stores are not saturated with Ca2+. Changes in pHo affected pHi. However, changes in pHi at constant pHo had no effect on hormone-evoked [Ca2+]i increase, reduction in [Ca2+]i after hormone stimulation, or reloading of intracellular stores. We conclude that the hormone-activated plasma membrane Ca2+ entry pathway responsible for Ca2+ reloading is directly modulated by external H+.
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pubmed:grant |
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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 |
http://linkedlifedata.com/resource/pubmed/chemical/4,4'-Diisothiocyanostilbene-2,2'-Dis...,
http://linkedlifedata.com/resource/pubmed/chemical/4-Acetamido-4'-isothiocyanatostilben...,
http://linkedlifedata.com/resource/pubmed/chemical/5-dimethylamiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Acetic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Acetic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Ammonium Chloride,
http://linkedlifedata.com/resource/pubmed/chemical/Atropine,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Carbachol,
http://linkedlifedata.com/resource/pubmed/chemical/Lanthanum,
http://linkedlifedata.com/resource/pubmed/chemical/Sincalide,
http://linkedlifedata.com/resource/pubmed/chemical/lanthanum chloride
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0002-9513
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
257
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
G917-24
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2610261-4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid,
pubmed-meshheading:2610261-4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid,
pubmed-meshheading:2610261-Acetic Acid,
pubmed-meshheading:2610261-Acetic Acids,
pubmed-meshheading:2610261-Amiloride,
pubmed-meshheading:2610261-Ammonium Chloride,
pubmed-meshheading:2610261-Animals,
pubmed-meshheading:2610261-Atropine,
pubmed-meshheading:2610261-Calcium,
pubmed-meshheading:2610261-Calcium Radioisotopes,
pubmed-meshheading:2610261-Carbachol,
pubmed-meshheading:2610261-Hydrogen-Ion Concentration,
pubmed-meshheading:2610261-Kinetics,
pubmed-meshheading:2610261-Lanthanum,
pubmed-meshheading:2610261-Pancreas,
pubmed-meshheading:2610261-Rats,
pubmed-meshheading:2610261-Rats, Inbred Strains,
pubmed-meshheading:2610261-Sincalide
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pubmed:year |
1989
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pubmed:articleTitle |
Modulation of agonist-activated calcium influx by extracellular pH in rat pancreatic acini.
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pubmed:affiliation |
Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235.
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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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