Dopamine (DA) release in the CNS is critical for motor control and motivated behaviors. Dysfunction of its regulation is thought to be implicated in drug abuse and in diseases such as schizophrenia and Parkinson's. Although various potassium channels located in the somatodendritic compartment of DA neurons such as G-protein-gated inward rectifying potassium channels (GIRK) have been shown to re...

We have examined the actions of histidine-specific reagents on potassium channels in squid giant axons. External application of 20-500 microM diethylpyrocarbonate (DEP) slowed the opening of potassium channels with little or no effect on closing rates. Sodium channels were not affected by these low external concentrations of DEP. Internal application of up to 2 mM DEP had no effect on potassium...

Opening of potassium channels on vascular smooth muscle cells with resultant hyperpolarization plays a central role in several mechanisms of vasodilation. For example, in the arteriolar circulation where tissue perfusion is regulated, there is an endothelial derived hyperpolarizing factor that opens vascular smooth muscle calcium-activated potassium channels, eliciting dilation. Metabolic vasod...

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 import...

Hyperpolarization-activated Cyclic Nucleotide-modulated (HCN) channels are similar in structure and function to voltage-gated potassium channels. Sequence similarity and functional analyses suggest that the HCN pore is potassium channel-like, consisting of a selectivity filter and an activation gate at the outer and inner ends, respectively. In GYG-containing potassium channels, the selectivity...

A non inactivating potassium current known as the delayed rectifier plays a major role in membrane repolarization during an action potential. Whereas several candidate genes exist that code for potassium current, the identities of the molecular isotypes that are responsible in situ for membrane repolarization remain unidentified. We report that Kv2 channels play a major role in action potential...

In order to understand the electrochemical behavior of a living cell at a low extracellular potassium concentration, a model is constructed. The model involves only the ATP driven sodium-potassium pump, and the sodium and potassium channels. Predictions of the model fit the N-shape of the current-voltage characteristic at low extracellular potassium. The model can, furthermore, quantitatively a...

Phosphorylation of potassium channels affects their function and plays a major role in regulating cell physiology. Here, we review previous studies of potassium channel phosphorylation, focusing first on studies employing site-directed mutagenesis of recombinant channels expressed in heterologous cells. We then discuss recent mass spectrometric-based approaches to identify and quantify phosphor...

Physiol. Soc.. ESSN: 1548-9221. Visit our website at http://www.the-aps.org/. American Physiological Society, 9650 Rockville Pike, Bethesda MD 20814-3991. ©2012 Int. Union Physiol. Sci./Am. the physiological developments. It is published bimonthly in February, April, June, August, October, and December by (formerly published as News in Physiological Science) publishes brief review articles on m...

Potassium channels and transporters maintain potassium homeostasis and play significant roles in several different biological actions via potassium ion regulation. In previous decades, the key revelations that potassium channels and transporters are involved in the production of gastric acid and the regulation of secretion in the stomach have been recognized. Drugs used to treat peptic ulcerati...