Hyperkalaemia, an elevated extracellular fluid potassium concentration, is a common electrolyte disorder and is present in 1-10% of hospitalised patients. Elevated serum potassium concentrations are usually asymptomatic but may be associated with electrocardiogram (ECG) changes. Hyperkalaemia occasionally leads to life-threatening cardiac arrhythmias. Prompt recognition of this disorder, patien...

We unveil a new homogeneous assay-using OliGreen and an ATP-binding aptamer-for the highly selective and sensitive detection of potassium ions.

The renal outer medullary potassium channel (ROMK, KCNJ1) mediates potassium recycling and facilitates sodium reabsorption through the Na(+)/K(+)/2Cl(-) cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Human genetic studies indicate that ROMK homozygous loss-of-function mutations cause type II Bartter syndrome, featuring polyuria, renal salt wasting, a...

"Low sodium" muscles were prepared which contained around 5 mmoles/kg fiber of intracellular sodium. "High sodium" muscles containing between 15 and 30 mmoles/kg fiber of intracellular sodium were also prepared. In low sodium muscles application of 10(-5)M strophanthidin reduced potassium influx by about 5%. Potassium efflux was unaffected by strophanthidin under these conditions. In high sodiu...

After healing of experimental myocardial infarction in cat hearts, endocardial cells demonstrate persistent regional electrical changes. These include long action potential duration in surviving cells over the infarct scar, and short action potential duration and low membrane potential in border zone cells between the scar and normal tissue. We studied the basis for these electrophysiological c...

1. In erythrocytes, the extrusion of a cell sodium load is accomplished by the ouabain-sensitive sodium-potassium pump and by the frusemide-sensitive sodium-potassium cotransport, which operate against the passive sodium permeability. All these three components of the cell sodium balance were studied in essential hypertension (410 subjects were investigated). 2. An abnormally low rate of net so...

Ciliary ganglion neurons, half of which normally suffer developmental death in the embryo, will survive in culture in medium supplemented with depolarizing concentrations of potassium. It is not known how elevated potassium acts inside the cell to promote survival. We report here that depolarizing concentrations of extracellular potassium promote neuronal survival by causing a sustained increas...

We review the design and fabrication of thin-film composite optical waveguides (OWG) with high refractive index for sensor applications. A highly sensitive optical sensor device has been developed on the basis of thin-film, composite OWG. The thin-film OWG was deposited onto the surface of a potassium-ion-exchanged (K(+)) glass OWG by sputtering or spin coating (5-9mm wide, and with tapers at b...

BACKGROUND Potassium channels play critical roles in the regulation of cell membrane potential, which is central to the excitability of myometrium. The ATP-sensitive potassium (KATP) channel is one of the most abundant potassium channels in myometrium. The objectives of this study were to investigate the protein expression of KATP channel in human myometrium and determine the levels of KATP cha...