Neuronal excitability relies on inward sodium and outward potassium fluxes during action potentials. To prevent neuronal hyperexcitability, potassium ions have to be taken up quickly. However, the dynamics of the activity-dependent potassium fluxes and the molecular pathways underlying extracellular potassium homeostasis remain elusive. To decipher the specific and acute contribution of astrogl...

BACKGROUND Previously, we reported that elevated extracellular potassium concentration in vitro inhibited proliferation and migration of vascular smooth muscle cells, formation of free radical compounds by macrophages, and reduced platelet sensitivity to agonists. More recently, we described a reduction in neointimal proliferation after balloon angioplasty injury in the carotid arteries of rats...

If a sartorius muscle of frog is pretreated for 30 min. with a hyposmotic Ringer's (called "hyposmotic potassium chloride") in which all sodium chloride is replaced by 23 mM potassium chloride, and then is immersed in normal Ringer's for about 40 min., a twitch of normal size can be elicited although the potassium contracture is almost completely abolished. During the time that this selective i...

Potassium is the most abundant metal ion in every living cell. This ion is essential due to its requirement for the activity of the ribosome and many enzymes but also because of its role in buffering the negative charge of nucleic acids. As the external concentrations of potassium are usually low, efficient uptake and intracellular enrichment of the ion is necessary. The Gram-positive bacterium...

PREVIOUS studies " have shown that a specific depressor response occurs in normotensive and hypertensive rats following deprivation of dietary potassium. Cortisone restores the lowered blood pressures of such potassium-deficient rats to their initial normotensive' 6 or hypertensive levels. Although a similar depressor response occurs in human subjects, when fed a potassium-deficient diet and in...

1. Fluid secretion by isolated salivary glands was stimulated by elevating the external potassium concentration. 2. The stimulatory effect of potassium was dependent on external calcium and was potentiated by a subthreshold dose of 5-hydroxytryptamine (5-HT). 3. During the action of 120 mM potassium there was a large calciumdependent decrease in transepithelial resistance similar to that produc...

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...

This study was carried out in order to evaluate the changes of Nitrogen, phosphor and potassium uptake by wheat and remaining of them in soil under foliar application of Leonardite and foliar application of N and K. The experiment was conducted in Gorgan University of Agricultural Sciences and Natural Resources during 2013- 2014. The experiment was laid out a using split-plot arrangement based ...

plant appropriate nutrition is one of the most important factors in improving the quality and quantity of product. providing adequate and balanced of plant nutrients is essential for achieving maximum potential production. potassium is one of the essential elements to plant’s growth. therefore, knowledge of soil potassium status is so important in order to optimum usage of potassium fertilizers...