Linked Life Data

10650982

Source:http://linkedlifedata.com/resource/pubmed/id/10650982

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-2-28
pubmed:abstractText
Feedback modulation of voltage-dependent Ca2+ channels by ATP is a well documented phenomenon in bovine chromaffin cells. However, its influence in the control of hormone release is at present poorly understood. By using combined patch-clamp and fura-2 fluorescence measurements we provide evidence that the three Ca2+ channel types (L, N and P/Q) expressed in bovine chromaffin cells are inhibited by ATP (30 microM), and that their involvement in the secretory response, as assayed by capacitance measurements, is roughly proportional to their contribution to the whole-cell Ca2+ current (ICa) both in the absence and presence of ATP. ATP did not modify the capacitance increase observed in cells dialyzed with Ca(2+)-EGTA buffers (1.5 microM free Ca2+), thus excluding a direct effect of ATP on the secretory machinery. Voltage predepolarizations or long chemical (2 s, 70 mM KCl) depolarizations attenuate the effect of ATP on exocytosis by partially relieving the inhibition of ICa Likewise, a strong stimulation that depletes the readily releasable pool of vesicles prevents an inhibitory effect of ATP on the secretory response. While these results lend support to the hypothesis of autocrine modulation of exocytosis by endogenously released ATP acting on P2y-purinoceptors to inhibit ICa, feedback regulation of the rate of release will be a complex function of the occupancy of those receptors and of the electrical and secretory activity of the cell.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
439
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
304-14
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Extracellular ATP regulates exocytosis in inhibiting multiple Ca(2+) channel types in bovine chromaffin cells.
pubmed:affiliation
Departamento de Farmacología y Terapéutica. Facultad de Medicine, Universidad Autónoma de Madrid, Spain.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't