Linked Life Data

21088885

Source:http://linkedlifedata.com/resource/pubmed/id/21088885

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2010-12-24
pubmed:abstractText
We have investigated the dynamics of the free [Ca(2+)] inside the secretory granules of neurosecretory PC12 and INS1 cells using a low-Ca(2+)-affinity aequorin chimera fused to synaptobrevin-2. The steady-state secretory granule [Ca(2+)] ([Ca(2+)](SG)] was around 20-40 ?M in both cell types, about half the values previously found in chromaffin cells. Inhibition of SERCA-type Ca(2+) pumps with thapsigargin largely blocked Ca(2+) uptake by the granules in Ca(2+)-depleted permeabilized cells, and the same effect was obtained when the perfusion medium lacked ATP. Consistently, the SERCA-type Ca(2+) pump inhibitor benzohydroquinone induced a rapid release of Ca(2+) from the granules both in intact and permeabilized cells, suggesting that the continuous activity of SERCA-type Ca(2+) pumps is essential to maintain the steady-state [Ca(2+)](SG). Both inositol 1,4,5-trisphosphate (InsP(3)) and caffeine produced a rapid Ca(2+) release from the granules, suggesting the presence of InsP(3) and ryanodine receptors in the granules. The response to high-K(+) depolarization was different in both cell types, a decrease in [Ca(2+)](SG) in PC12 cells and an increase in [Ca(2+)](SG) in INS1 cells. The difference may rely on the heterogeneous response of different vesicle populations in each cell type. Finally, increasing the glucose concentration triggered a decrease in [Ca(2+)](SG) in INS1 cells. In conclusion, our data show that the secretory granules of PC12 and INS1 cells take up Ca(2+) through SERCA-type Ca(2+) pumps and can release it through InsP(3) and ryanodine receptors, supporting the hypothesis that secretory granule Ca(2+) may be released during cell stimulation and contribute to secretion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1573-6830
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1267-74
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Ca2+ dynamics in the secretory vesicles of neurosecretory PC12 and INS1 cells.
pubmed:affiliation
Instituto de Biología y Genética Molecular, Departamento de Bioquímica y Biología Molecular y Fisiología, Facultad de Medicina, Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Ramón y Cajal, 7, 47005 Valladolid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't