| dc.creator | MEARS,DAVID | |
| dc.creator | ROJAS,EDUARDO | |
| dc.date | 2006-01-01 | |
| dc.date.accessioned | 2019-05-02T21:21:33Z | |
| dc.date.available | 2019-05-02T21:21:33Z | |
| dc.identifier | https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0716-97602006000300012 | |
| dc.identifier.uri | http://revistaschilenas.uchile.cl/handle/2250/81678 | |
| dc.description | We 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. | |
| dc.format | text/html | |
| dc.language | en | |
| dc.publisher | Sociedad de Biología de Chile | |
| dc.relation | 10.4067/S0716-97602006000300012 | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.source | Biological Research v.39 n.3 2006 | |
| dc.subject | islet of Langerhans | |
| dc.subject | insulin | |
| dc.subject | stimulus-secretion coupling | |
| dc.subject | ion channel | |
| dc.subject | inactivation kinetics | |
| dc.subject | BAPTA | |
| dc.title | Properties of voltage-gated Ca2+ currents measured from mouse pancreatic β-cells in situ | |
