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dc.creatorMEARS,DAVID
dc.creatorROJAS,EDUARDO
dc.date2006-01-01
dc.date.accessioned2019-05-02T21:21:33Z
dc.date.available2019-05-02T21:21:33Z
dc.identifierhttps://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300012
dc.identifier.urihttp://revistaschilenas.uchile.cl/handle/2250/81678
dc.descriptionWe used the single-microelectrode voltage-clamp technique to record ionic currents from pancreatic β-cells within intact mouse islets of Langerhans at 37C, 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 β-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 β-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 β-cells in situ for determining the roles of ion channels in electrical activity and insulin secretion.
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dc.languageen
dc.publisherSociedad de Biología de Chile
dc.relation10.4067/S0716-97602006000300012
dc.rightsinfo:eu-repo/semantics/openAccess
dc.sourceBiological Research v.39 n.3 2006
dc.subjectislet of Langerhans
dc.subjectinsulin
dc.subjectstimulus-secretion coupling
dc.subjection channel
dc.subjectinactivation kinetics
dc.subjectBAPTA
dc.titleProperties of voltage-gated Ca2+ currents measured from mouse pancreatic β-cells in situ


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