Linked Life Data

8458074

Source:http://linkedlifedata.com/resource/pubmed/id/8458074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-4-27
pubmed:abstractText
Agonist- and inositol 1,4,5-trisphosphate (InsP3)-evoked responses in Xenopus oocytes utilize calcium mobilized from cellular stores as well as from the medium. We studied the effect of the status of Ca stores on InsP3-induced Ca entry. Thapsigargin (TG) caused a net increase of 45Ca2+ efflux from oocytes in a time and dose dependent manner (31 and 54% of total label, at 30 and 60 min, respectively). Incubation with TG (60 min) resulted in a complete loss of the response to InsP3 implying that InsP3-sensitive Ca stores were depleted. Challenge with 1.8 mM Ca2+ resulted in a large depolarizing chloride current (1231 +/- 101 nA) which was not further potentiated by InsP3. This suggested that extensive depletion of cellular Ca stores is sufficient to induce maximal entry of extracellular Ca (Cao). Following the injection of InsP3, a much more limited loss of cellular Ca was sufficient to produce large Ca entry. Dimethyl sulfoxide (DMSO) alone, the vehicle used to dissolve TG, did not cause increase in either efflux of 45Ca2+, nor in the Cao-evoked Cl- current. It did, however, markedly potentiate this current following the injection of InsP3. DMSO moderately inhibited InsP3-induced 45Ca2+ efflux from oocytes. Hence, apparent potentiation of Ca entry can be observed without additional depletion of cellular Ca. We conclude that Ca entry may be induced via either stimulation with InsP3 and limited Ca depletion or depletion of a specific and, possibly small, cellular Ca store alone. The mechanism of DMSO potentiation is unknown, but may be important in view of the universal use of this solvent as vehicle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0143-4160
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
101-10
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Calcium entry in Xenopus oocytes: effects of inositol trisphosphate, thapsigargin and DMSO.
pubmed:affiliation
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't