Participation Of Na(+) Channels In The Potentiation By Tityus Serrulatus Alpha-toxin Tstx-v Of Glucose-induced Electrical Activity And Insulin Secretion In Rodent Islet Beta-cells.

dc.creatorGonçalves, Antonio A
dc.creatorToyama, Marcos H
dc.creatorCarneiro, Everardo M
dc.creatorMarangoni, Sergio
dc.creatorArantes, Eliana C
dc.creatorGiglio, José R
dc.creatorBoschero, Antonio C
dc.date2003-Jun
dc.date2015-11-27T12:52:17Z
dc.date2015-11-27T12:52:17Z
dc.date.accessioned2018-03-29T00:57:43Z
dc.date.available2018-03-29T00:57:43Z
dc.identifierToxicon : Official Journal Of The International Society On Toxinology. v. 41, n. 8, p. 1039-45, 2003-Jun.
dc.identifier0041-0101
dc.identifier
dc.identifierhttp://www.ncbi.nlm.nih.gov/pubmed/12875879
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/195455
dc.identifier12875879
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1295688
dc.descriptionThe effects of TsTx-V, an alpha-toxin isolated from Tityus serrulatus venom, on electrical activity and insulin secretion by rodent pancreatic islet cells were studied. TsTx-V (5.6 microg/ml) depolarized mouse pancreatic beta-cells, diminished the membrane input resistance and increased the duration of the active phase of glucose-induced electrical activity. Similar results were observed with the Na(+) channel agonist veratridine (110 microM). Both agents potentiated glucose (8.3 mM)-induced insulin secretion in rat islet. In the presence of TsTx-V or veratridine, insulin secretion increased 2- and 1.4-fold over basal values, respectively (P<0.001). The Na(+) channel antagonist tetrodotoxin (6 microM) significantly decreased glucose- and TsTx-V-induced insulin secretion (P<0.001). TsTx-V also stimulated insulin secretion at low glucose concentrations (2.8 mM) whereas the beta-toxin, Ts-gamma (gamma toxin), also obtained from Tityus serrulatus venom, significantly reduced TsTx-V-induced secretion at sub- and suprathreshold concentrations of glucose. These results are consistent with a model whereby Na(+) channels participate in glucose-induced electrical activity. Alteration in the activity of these channels changes the length of time during which the beta-cell depolarizes, thereby altering the secretory behavior of the cell. The construction of a three-dimensional model for TsTx-V revealed a conserved core containing an alpha-helix and three beta-strands, with minor differences when compared with toxins from other scorpion venoms.
dc.description41
dc.description1039-45
dc.languageeng
dc.relationToxicon : Official Journal Of The International Society On Toxinology
dc.relationToxicon
dc.rightsfechado
dc.rights
dc.sourcePubMed
dc.subjectAnimals
dc.subjectB-lymphocytes
dc.subjectElectric Conductivity
dc.subjectGlucose
dc.subjectInsulin
dc.subjectIslets Of Langerhans
dc.subjectMice
dc.subjectMolecular Conformation
dc.subjectNeurotoxins
dc.subjectPhylogeny
dc.subjectRats
dc.subjectScorpion Venoms
dc.subjectScorpions
dc.subjectSodium Channel Agonists
dc.subjectSodium Channels
dc.subjectTetrodotoxin
dc.subjectVeratridine
dc.titleParticipation Of Na(+) Channels In The Potentiation By Tityus Serrulatus Alpha-toxin Tstx-v Of Glucose-induced Electrical Activity And Insulin Secretion In Rodent Islet Beta-cells.
dc.typeArtículos de revistas


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