Intracellular calcium mobilization by muscarinic receptors is regulated by micromolar concentrations of external Ca2+

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dc.contributor.authorSmaili, Soraya Soubhi [UNIFESP]
dc.contributor.authorCarvalho, Solange Maria Torchia [UNIFESP]
dc.contributor.authorCavalcanti, Paulo MS [UNIFESP]
dc.contributor.authorJurkiewicz, Neide H. [UNIFESP]
dc.contributor.authorGarcia, Antonio G.
dc.contributor.authorJurkiewicz, Aron [UNIFESP]
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.contributor.institutionUniv Autonoma Madrid
dc.date.accessioned2016-01-24T12:31:24Z
dc.date.available2016-01-24T12:31:24Z
dc.date.issued2001-06-01
dc.description.abstractCarbachol-induced contractions of rat stomach fundus strips, obtained in a nutrient solution containing 1.8 mM Ca2+, were resistant to Ca2+ withdrawal, even after 1 h of bathing the tissues in a nominal 0 Ca2+ solution. This was not observed when K+ was used to evoke contractions, which were rapidly inhibited after Ca2+ removal (t(1/)2=2 min). the effect of carbachol in 0 Ca2+ solution was reduced by using drugs that reduce intracellular pools of Ca2+, such as caffeine (1-3 mM), ryanodine (30 muM) or thapsigargin (1 muM), corroborating the involvement of intracellular Ca2+ stores. On the other hand, when the 0 Ca2+ solution contained EGTA, a complete decline of carbachol effects was observed within about 8 min, indicating the involvement of extracellular Ca2+. Atomic absorption spectrometry showed that our 0 Ca2+ solution still contained 45 muM Ca2+, which was drastically reduced to 5.9 nM in the presence of EGTA. Taken together, our results indicate that the effects of carbachol are due to the mobilization of caffeine-, ryanodine- and thapsigargin-sensitive intracellular Ca2+ stores, and that these stores are not inactivated or depleted if micromolar concentrations (45 muM), but not nanomolar concentrations (5.9 nM) of Ca2+ are maintained in the extracellular milieu.en
dc.description.affiliationUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, BR-04044020 São Paulo, Brazil
dc.description.affiliationUniv Autonoma Madrid, Dept Pharmacol, Madrid, Spain
dc.description.affiliationUnifespUniversidade Federal de São Paulo, Escola Paulista Med, Dept Pharmacol, BR-04044020 São Paulo, Brazil
dc.description.sourceWeb of Science
dc.format.extent376-382
dc.identifierhttp://dx.doi.org/10.1007/s004240100535
dc.identifier.citationPflugers Archiv-european Journal of Physiology. New York: Springer-verlag, v. 442, n. 3, p. 376-382, 2001.
dc.identifier.doi10.1007/s004240100535
dc.identifier.issn0031-6768
dc.identifier.urihttp://repositorio.unifesp.br/handle/11600/26568
dc.identifier.wosWOS:000169629100008
dc.language.isoeng
dc.publisherSpringer
dc.relation.ispartofPflugers Archiv-european Journal of Physiology
dc.rightsinfo:eu-repo/semantics/restrictedAccess
dc.rights.licensehttp://www.springer.com/open+access/authors+rights?SGWID=0-176704-12-683201-0
dc.subjectcaffeineen
dc.subjectcalciumen
dc.subjectcarbacholen
dc.subjectryanodineen
dc.subjectstomach fundusen
dc.subjectthapsigarginen
dc.titleIntracellular calcium mobilization by muscarinic receptors is regulated by micromolar concentrations of external Ca2+en
dc.typeinfo:eu-repo/semantics/article
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