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Authordc.contributor.authorMears, David 
Authordc.contributor.authorRojas, Eduardo es_CL
Admission datedc.date.accessioned2009-05-12T15:06:54Z
Available datedc.date.available2009-05-12T15:06:54Z
Publication datedc.date.issued2006
Cita de ítemdc.identifier.citationBIOLOGICAL RESEARCH Volume: 39 Issue: 3 Pages: 505-520 Published: 2006en
Identifierdc.identifier.issn0716-9760
Identifierdc.identifier.urihttps://repositorio.uchile.cl/handle/2250/127824
Abstractdc.description.abstractWe used the single-microelectrode voltage-clamp technique to record ionic currents from pancreatic beta-cells within intact mouse islets of Langerhans at 37 degrees C, the typical preparation for studies of glucose-induced "bursting" electrical activity. Cells were impaled with intracellular microelectrodes, and voltage pulses were applied in the presence of tetraethylammonium. Under these conditions, a voltage-dependent Ca2+ current (I-cav), containing L-type and non-L-type components, was observed. The current measured in situ was larger than that measured in single cells with whole-cell patch clamping, particularly at membrane potentials corresponding to the action potentials of beta-cell electrical activity. The temperature dependence of I-Cav was not sufficient to account for the difference in size of the currents recorded with the two methods. During prolonged pulses, the voltage-dependent Ca2+ current measured in situ displayed both rapid and slow components of inactivation. The rapid component was Ca2+-dependent and was inhibited by the membrane-permeable Ca2+ chelator, BAPTA-AM. The effect of BAPTA-AM on beta-cell electrical activity then demonstrated that Ca2+-dependent inactivation of I-cav contributes to action potential repolarization and to control of burst frequency. Our results demonstrate the utility of voltage clamping beta-cells in situ for determining the roles of ion channels in electrical activity and insulin secretion.en
Lenguagedc.language.isoesen
Publisherdc.publisherSOCIEDAD BIOLGIA CHILEen
Keywordsdc.subjectINDUCED ELECTRICAL-ACTIVITYen
Títulodc.titleProperties of voltage-gated Ca2+ currents measured from mouse pancreatic beta-cells in situen
Document typedc.typeArtículo de revista


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