Forskolin-induced block of delayed rectifying K+ channels in pancreatic?-cells is not mediated by cAMP

Abstract
K+ channels in the membrane of murine pancreatic β-cells were studied using the patch-clamp technique. The delayed outward current was activated in whole-cell experiments by depolarizing voltage pulses to potentials between −30 mV and 0 mV. Forskolin blocked the current rapidly (2+- and ATP-dependent K+ channels were influenced only weakly or not at all. It is therefore concluded that the 10-pS channel generates most of the delayed outward K+ current in murine pancreatic β-cells. The Ca2+-independent part of the delayed outward current in bovine adrenal chromaffin cells was also blocked by forskolin (100 μM).