L-type Ca-channel activity recorded at a low divalent cation concentration
Ashcroft FM., Smith PA., Fewtrell C.
We have examined the voltage-dependent properties of single L-type Ca channels in cell-attached patches on mouse pancreatic β-cells using 10 mM Ba2+ as the charge carrier, a Ba-concentration that produces minimal voltage shift. The voltage dependence of channel activation was consistent with the participation of L-type Ca channels in both the plateau potential and the action potential phases of β-cell electrical activity. In addition, single channel currents were observed at the resting potential suggesting Ca2+ influx through these L-type Ca channels contributes to background Ca2+ entry into the β-cell.