BK channels mediate a novel ionic mechanism that regulates glucose-dependent electrical activity and insulin secretion in mouse pancreatic β-cells.

BK channels are large unitary conductance K(+) channels cooperatively activated by intracellular calcium and membrane depolarisation. We show that BK channels regulate electrical activity in β-cells of mouse pancreatic islets exposed to elevated glucose. In 11.

Temporal profile of potassium channel dysfunction in cerebrovascular smooth muscle after experimental subarachnoid haemorrhage.

The pathogenesis of cerebral vasospasm after subarachnoid haemorrhage (SAH) involves sustained contraction of arterial smooth muscle cells that is maximal 6-8 days after SAH. We reported that function of voltage-gated K+ (KV) channels was significantly decreased during vasospasm 7 days after SAH in dogs. Since arterial constriction is regulated by membrane potential that in turn is determined predominately by K+ conductance, the compromised K+ channel dysfunction may cause vasospasm.

Preserved BK channel function in vasospastic myocytes from a dog model of subarachnoid hemorrhage.

Cerebral vasospasm after subarachnoid hemorrhage (SAH) is due to contraction of smooth muscle cells in the cerebral arteries. The mechanism of this contraction, however, is not well understood. Smooth muscle contraction is regulated in part by membrane potential, which is determined by K+ conductance in smooth muscle.

Modulation of recombinant and native neuronal SK channels by the neuroprotective drug riluzole.

Small conductance, Ca(2+)-activated K(+) channels (SK channels) regulate neuronal excitability. We used patch clamp to study the actions of the neuroprotective drug riluzole on recombinant SK2 channels expressed in HEK293 cells and native SK channels underlying the afterhyperpolarization current (I(AHP)) in cultured hippocampal neurons. External riluzole activated whole-cell SK2 channel currents in HEK293 cells dialyzed with a Ca(2+)-free intracellular solution.

Giant excised patch recordings of recombinant ion channel currents expressed in mammalian cells.

The giant excised patch variant of patch clamp recording combines microsecond time resolution of macroscopic currents with rapid exchange of the experimental solutions at the intracellular membrane surface. This technique has been applied to a limited number of cell types, including Xenopus oocytes, muscle cells, and photoreceptors. We have applied this technique to recording recombinant ion channel currents expressed in membrane patches excised from HEK293 cell lines.