1. The maximal rate of activity of sodium extrusion by the sodium pump, Na+--K+ outward cotransport, passive permeability to sodium and potassium, Na+--Li+ countertransport, and passive permeability to lithium were measured in 45 essential hypertensive patients, 24 young normotensive subjects with at least one hypertensive parent and 24 normotensive subjects with both parents normotensive. 2. T...

This study investigates the effect of variations in mineralocorticoid as well as cell sodium delivery and uptake on Na-K-ATPase activity in the mouse medullary thick ascending limb of Henle (mTALH). Pharmacologic doses of the mineralocorticoid deoxycorticosterone acetate (DOCA) resulted in a 28% increase of Na-K-ATPase activity. Furosemide-induced inhibition of sodium uptake by the mTALH cell a...

Voltage-dependent sodium channels are uniformly distributed along unmyelinated axons, but are highly concentrated at nodes of Ranvier in myelinated axons. Here, we show that this pattern is associated with differential localization of distinct sodium channel alpha subunits to the unmyelinated and myelinated zones of the same retinal ganglion cell axons. In adult axons, Na(v)1.2 is localized to ...

Isolated adult rat heart cells in suspension were loaded with sodium by incubation with ouabain in the absence of calcium for 30 minutes. Addition of low levels of calcium induced accelerated rates of sodium influx and efflux, as measured with 22Na. The magnitude of calcium-induced 22Na efflux was 50-fold greater than the net rate of calcium uptake and required extracellular sodium, but not ext...

Voltage-gated sodium channels are essential for the initiation and propagation of action potentials in excitable cells and are known as a target of local anesthetics. In addition, inhibition of sodium channels by volatile anesthetics has been proposed as a mechanism of general anesthesia. The n-alcohols produce anesthesia, and their potency increases with carbon number until a "cut-off" is reac...

Na(x) is an atypical sodium channel that is assumed to be a descendant of the voltage-gated sodium channel family. Our recent studies on the Na(x)-gene-targeting mouse revealed that Na(x) channel is localized to the circumventricular organs (CVOs), the central loci for the salt and water homeostasis in mammals, where the Na(x) channel serves as a sodium-level sensor of the body fluid. To unders...

Understanding the mechanisms of sodium (Na⁺) influx, effective compartmentalization, and efflux in higher plants is crucial to manipulate Na⁺ accumulation and assure the maintenance of low Na⁺ concentration in the cytosol and, hence, plant tolerance to salt stress. Na⁺ influx across the plasma membrane in the roots occur mainly via nonselective cation channels (NSCCs). Na⁺ is compartmentalized ...

Voltage-gated sodium channelopathies underlie many excitability disorders. Genes SCN1A, SCN2A and SCN9A, which encode pore-forming alpha-subunits Na(V)1.1, Na(V)1.2 and Na(V)1.7, are clustered on human chromosome 2, and mutations in these genes have been shown to underlie epilepsy, migraine, and somatic pain disorders. SCN3A, the gene which encodes Na(V)1.3, is part of this cluster, but until r...

In order to evaluate the possible role of sodium- and potassium-activated adenosine triphosphatase in the active transport of sodium by the renal tubules, we examined the effect of large changes in the tubular reabsorptive load of sodium on the Na-K-ATPase activity of rat kidney homogenates. Glomerular filtration and tubular reabsorption of sodium per gram of kidney tissue increased progressive...

in this research, the groundwater quality of hoz–e–soltan lake and its catchment was studied for drinking, domestic and irrigation uses according to different parameters. this lake with 195 km2 catchment area is located 85 km of southwest of tehran–qom highway. in order to investigate groundwater quality characteristics in the study area, 34 data from water of well belong to 2008 selected to pr...