During ischemic stroke, a fatal biochemical cascade that results in neuronal hyperexcitability is initiated when neurons at risk are exposed to excessive excitatory amino acids and pathologically high levels of intracellular calcium (Ca(2+)). Therefore, neuroprotectants including NMDA-antagonists and blockers of voltage-gated Ca(2+) channels have been proposed as novel strategies for stroke tre...

We examined the effects of Pandinus imperator scorpion venom on voltage-gated potassium channels in cultured clonal rat anterior pituitary cells (GH3 cells) using the gigohm-seal voltage-clamp method in the whole-cell configuration. We found that Pandinus venom blocks the voltage-gated potassium channels of GH3 cells in a voltage-dependent and dose-dependent manner. Crude venom in concentration...

Potassium channels vary in their function and regulation, yet they maintain a number of important features - they are involved in the control of potassium flow, cell volume, cell membrane resting potential, cell excitability and hormone release. The potassium (K(+)) inward rectifier (Kir) superfamily of channels are potassium selective channels, that are sensitive to the concentration of K(+) i...

Small conductance Ca(2+)-activated potassium channels (SK channels) distributing in the nervous system play an important role in learning, memory and synaptic plasticity. Most pharmacological properties of them are determined by short-chain scorpion toxins. Different from most voltage-gated potassium channels and large-conductance Ca(2+)-activated potassium channels, SK channels are only inhibi...

Discussion A method for identification of potassium channel sequences must provide a high sensitity and a good differentiation between true and false positives. This method was tested against the swissprot compilation. As it becomes evident from figure XX, there's a strict separation between true and false positives. To prevent poor recognition of unknown potassium channels, it must be made sur...

Potassium channels are pore-forming transmembrane proteins that regulate a multitude of biological processes by controlling potassium flow across cell membranes. Aberrant potassium channel functions contribute to diseases such as epilepsy, cardiac arrhythmia, and neuromuscular symptoms collectively known as channelopathies. Increasing evidence suggests that cancer constitutes another category o...

UNLABELLED Several reports suggest that clinically used concentrations of inhaled anesthetics can increase conductance through noninactivating potassium channels and that the resulting hyperpolarization might decrease excitability, thereby leading to the anesthetic state. We speculated that animals deficient in such potassium channels might be resistant to the effects of anesthetics. Thus, in t...

Aim: This study was conducted to test the selectivity of a class III antiarrhythmic agent, DC031050, on cardiac hERG and neuronal potassium channels. Methods: Whole-cell voltage patch clamp was used. Results: We previously reported that DC031050, a derivative of dofetilide, exhibited more potent biological activity than its leading compound, dofetilide. Here, we show that DC031050 selectively i...

To study the potential role of potassium channels in the taste response to potassium salts, we applied 4-aminopyridine (4-AP) to the anterior rat tongue and recorded chorda tympani nerve taste responses to chemical stimuli. 4-aminopyridine is a pharmacological blocker that reduces potassium conductance through potassium channels in nerve and muscle. Summated neural responses to stimuli dissolve...

Potassium is the most abundant cation and a myriad of transporters regulate K(+) homeostasis in plant. Potassium plays a role as a major osmolyte to regulate stomatal movements that control water utility of land plants. Here we report the characterization of two inward rectifying shaker-like potassium channels, OsKAT2 and OsKAT3, expressed in guard cell of rice plants. While OsKAT2 showed typic...