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rdf:type |
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lifeskim:mentions |
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pubmed:dateCreated |
1990-7-12
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pubmed:abstractText |
1. The free cytoplasmic Ca2+ concentration ([Ca2+]i) can be measured using Fura-2 in superfused single human umbilical vein endothelial cells. When an endothelial cell is stimulated by a maximal dose of histamine (100 microM), [Ca2+]i rises to a peak and then falls back to a maintained plateau which is due to a stimulated Ca2+ influx. 2. If extracellular Ca2+ is replaced by 50 microM-Mn2+ then 100 microM-histamine causes a rise in [Ca2+]i accompanied by a fluorescence quench that signals the stimulated entry of Mn2+ into the cytoplasm. 3. If in Ca2(+)-free solution a cell is stimulated by 100 microM-histamine for 120 s to discharge the internal Ca2+ store, and then exposed to 50 microM-Mn2+ after removal of the histamine, a similar stimulated Mn2+ entry is seen. This quench is unaffected by readdition of histamine and is not seen if the store is refilled by exposure to 1 mM-extracellular Ca2+ for 180 s before exposure to the Mn2+. 4. The refilling of the internal store by exposure to 1 mM-Ca2+ and the stimulated entry of Mn2+ are both blocked by 2 mM-Ni2+. 5. If [Ca2+]i is stimulated to produce repetitive spikes by a low dose of histamine (0.3-1 microM) in nominally Ca2(+)-free solution containing Mn2+, then the stimulated quench is uniform and is not modulated by the [Ca2+]i spiking. 6. If the internal store is discharged by exposure to histamine in Ca2(+)-free solution and then refilled for a short period then the cell is in a state where the internal store is partly full to an extent that depends on the duration of the refilling. In such an experiment, the rate of Mn2+ influx may be estimated by measuring the rate of quench during a short exposure to 50 microM-Mn2+. The rate of Mn2+ entry varies inversely with the degree of fullness of the internal Ca2+ store. 7. If a similar experiment is repeated but with the fullness of the internal store being varied by varying the period of the initial exposure to 100 microM-histamine, with no refilling, the same inverse relationship between Mn2+ influx and fullness of the internal store is obtained. 8. These experiments show that Mn2+ enters human umbilical vein endothelial cells following agonist stimulation by a pathway that is controlled by the degree of fullness of the internal store; it does not, however, enter the cytoplasm by exactly the same route as Ca2+.(ABSTRACT TRUNCATED AT 400 WORDS)
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2408921,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2419482,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2420465,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2431318,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2434867,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2439098,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2439921,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2446148,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2451020,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2455713,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2457169,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2457808,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2536366,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2541679,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2650680,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2670242,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2730577,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-2845795,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3034250,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3136659,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3196311,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3197920,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3291862,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3354649,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3360779,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3675593,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3680283,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3693357,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3782301,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3827881,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-3838314,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-6185669,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2348402-6803225
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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 |
Feb
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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:volume |
421
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
55-77
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
pubmed-meshheading:2348402-Action Potentials,
pubmed-meshheading:2348402-Benzofurans,
pubmed-meshheading:2348402-Calcium,
pubmed-meshheading:2348402-Cells, Cultured,
pubmed-meshheading:2348402-Endothelium, Vascular,
pubmed-meshheading:2348402-Fluorescent Dyes,
pubmed-meshheading:2348402-Fura-2,
pubmed-meshheading:2348402-Histamine,
pubmed-meshheading:2348402-Humans,
pubmed-meshheading:2348402-Manganese,
pubmed-meshheading:2348402-Nickel,
pubmed-meshheading:2348402-Stimulation, Chemical,
pubmed-meshheading:2348402-Umbilical Veins
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pubmed:year |
1990
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pubmed:articleTitle |
Agonist-stimulated divalent cation entry into single cultured human umbilical vein endothelial cells.
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pubmed:affiliation |
Smith Kline & French Research Ltd, Welwyn, Herts.
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pubmed:publicationType |
Journal Article
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