Voltage-sensitive K+ channels were studied in rat cerebellar Purkinje neurons in culture using the single-channel recording technique. Recordings in the cell-attached and outside-out configuration revealed multiple voltage-sensitive K+ channel types in patches from both the somatic and the dendritic regions. K+ channel types were present in all patches studied. The same channel types were obser...

The channels belonging to the KCNQ gene family consist of 5 different subtypes, which assemble as pentameric channels. The KCNQ2-5 subunits are highly expressed in the ventrobasal thalamus (VB) where they function primarily as KCNQ2/3 heteromers. They underlie an outward potassium (K+)-current, called M-current (IM), which provides a hyperpolarizing drive, thus regulating neuronal excitability....

A series of 172 molecular structures that block the hERG K(+) channel were used to develop a classification model where, initially, eight types of PaDEL fingerprints were used for k-nearest neighbor model development. A consensus model constructed using Extended-CDK, PubChem and Substructure count fingerprint-based models was found to be a robust predictor of hERG activity. This consensus model...

The ROMK channel plays an important role in K recycling in the thick ascending limb (TAL) and K secretion in the cortical collecting duct (CCD). A large body of evidence indicates that the ROMK channel is a key component of the native K secretory channel identified in the apical membrane of the TAL and the CCD. Although the ROMK channel shares several key regulatory mechanisms with the native K...

Tertiapin is a 21-residue peptide isolated from honey bee venoms. A recent study indicated that tertiapin is a potent blocker of certain types of inwardly rectifying K(+) (Kir) channels (). We examined the effect of tertiapin on ion channel currents in rabbit cardiac myocytes using the patch-clamp technique. In the whole-cell configuration, tertiapin fully inhibited acetylcholine (1 microM)-ind...

Mechanosensitive ion channels have been described in many types of cells. These channels are believed to transduce pressure signals into intracellular biochemical and physiological events. In this study, the patch-clamp technique was used to identify and characterize a mechanosensitive ion channel in rat atrial cells. In cell-attached patches, negative pressure in the pipette activated an ion c...

We have measured gating currents from the squid giant axon using solutions that preserve functional K channels and with experimental conditions that minimize Na channel contributions to these currents. Two pharmacological agents were used to identify a component of gating current that is associated with K channels. Low concentrations of internal Zn2+ that considerably slow K channel ionic curre...

To determine whether K+-channel activation mediates shear stress-induced pulmonary vasodilation in the fetus, we studied the hemodynamic effects of K+-channel blockers on basal pulmonary vascular resistance and on the pulmonary vascular response to partial compression of the ductus arteriosus (DA) in chronically prepared late-gestation fetal lambs (128-132 days gestation). Study drugs included ...

K channels in the cell membrane of the insulin-secreting RINm5F cell line were studied using the patch-clamp technique in cell-attached patch mode. With 140 mM K in the pipette, two channels displaying different conductive and kinetics properties were observed. A voltage-independent, inward-rectifying, 55-pS channel was active at rest (no glucose, -70 mV), but was almost completely inhibited by...

Using rat ventricular cells, we studied the actions of free fatty acids and their ability to modulate the ATP-sensitive K' channel and to activate a new type of ATP-insensitive K' channel previously identified in rat atrial cells. Perfusion of the cytoplasmic face of the membrane with unsaturated fatty acids (10-50 ,M) such as arachidonic, linoleic, and eicosatrienoic acids inhibited the ATP-se...