Inwardly rectifying potassium channels (Kir) are a special subset of potassium selective ion channels which pass potassium more easily into rather than out of the cell. These channels mediate a variety of cellular functions, including control of membrane resting potential, maintenance of potassium homeostasis and regulation of cellular metabolism. Given the existence of fifteen Kir genes in mam...

Potassium release through ATP-sensitive potassium (K(ATP)) channels contributes to hypoxic vasodilation in the skeletal muscle vascular bed: It is uncertain whether K(ATP) channels on muscle cells contribute to the process. Potassium from muscle cells must cross the interstitial space to reach the vascular tissues, whereas that from vascular endothelium would have a higher concentration in veno...

BACKGROUND AND PURPOSE Potassium channels are important regulators of resting tone in large cerebral arteries, but their activity and distribution may vary according to vessel location and species studied. In the cerebral microcirculation in vivo, however, these channels appear to be silent at rest. Our goal was to determine the activity of potassium channels of brain arterioles from 2 origins ...

A 20 amino acid synthetic peptide, corresponding to the amino-terminal region of the Shaker B (ShB) K+ channel and responsible for its fast inactivation, can block large conductance Ca(2+)-dependent K+ channels from rat brain and muscle. The ShB inactivation peptide produces two kinetically distinct blocking events in these channels. At lower concentrations, it produces short blocks, and at hig...

Inflammatory molecules sensitize peripheral nociceptors, making them responsive to innocuous stimuli. Sensitization is mediated by protein kinase A (PKA), but the ion channels involved are not known. PKA increases expression of voltage-gated sodium channels, but knock-out of these channels does not eliminate inflammation-induced sensitization. PKA also decreases potassium currents, but the perc...

Introduction: we have recently reported the presence of two potassium currents with 598 and 368 pS conductance in the rough endoplasmic reticulum (RER) membrane. The 598 pS channel was voltage dependent and ATP sensitive. However, the 368 pS channel was rarely observed and its identity remained obscure. Since cationic channels in intracellular organelles such as mitochondria and RER play imp...

Nicorandil is an antianginal agent with nitrate-like and ATP-sensitive potassium channel activator properties. After activation of potassium channels, potassium ions are expelled out of the cells, which lead to membrane hyperpolarization, closure of voltage-gated calcium channels, and finally vasodilation. We present a uremic case suffering from repeated junctional bradycardia, especially befor...

The Slack and Slick genes encode potassium channels that are very widely expressed in the central nervous system. These channels are activated by elevations in intracellular sodium, such as those that occur during trains of one or more action potentials, or following activation of non-selective cationic neurotransmitter receptors such as AMPA receptors. This review covers the cellular and molec...

In many cell types rises in cytosolic calcium, either due to influx from the extracellular space, or by release from an intracellular store activates calcium dependent potassium currents on the plasmalemma. In neurons, these currents are largely activated following calcium influx via voltage gated calcium channels active during the action potentials. Three types of these currents are known: I(c...

A subset of potassium channels is regulated primarily by changes in the cytoplasmic concentration of ions, including calcium, sodium, chloride, and protons. The eight members of this subfamily were originally all designated as calcium-activated channels. More recent studies have clarified the gating mechanisms for these channels and have documented that not all members are sensitive to calcium....