Sodium efflux from rings of frog stomach muscle was measured at 5 degrees and 15 degrees C in three different steady states. After incubation in normal, K-free, or ouabain (10(-4)M) solutions, intracellular cations stabilized at markedly differing levels. At 5 degrees C, inhibition of Na extrusion was shown in the rate coefficients for (22)Na efflux, which were slightly smaller in K-free than i...

The membrane potential of frog sartorius muscle fibers in a Cl- and Na-free Ringer's solution when sucrose replaces NaCl is about the same as that in normal Ringer's solution. The K(+) efflux is also about the same in the two solutions but muscles lose K and PO(4) in sucrose Ringer's solutions. The membrane potential in sucrose Ringer's solution is equal to that given by the Nernst equation for...

AbstractThis study was undertaken to better understand the probable mechanisms of salt stress tolerance induced by seed priming of salicylic acid (SA) in barley. The barley seeds were pre-soaked by SA or water and then sown under different saline watering regimes including 0.62 (tapwater), 5, 10 and 15 dS m-1 in petri dishes and trend of water absorbing, seedling growth, germination rate and pe...

The presence of (Na(+)+K+)ATPase activity in CL14 clone and NIH NTY strain of Trypanosoma cruzi epimastigotes is demonstrated. A Na+ plus K+ stimulated ATPase activity is found in both strains. The optimal Na+/K+ ratio is 5:1 and 9:1 in CL14 clone and NIH NTY strain, respectively. In both strains, vanadate completely inhibits the ouabain-sensitive ATPase activity indicating that it belongs to t...

In Source Location (SL) problems the goal is to select a minimum cost source set S such that the connectivity from S to any node v is at least the demand dv of v. In Network Augmentation (NA) problems we are given a graph G = (V,E) and an edge-set F on V , edge-costs on F or node-costs on V , and connectivity requirements {rsv : sv ∈ D} on a set D of “demand edges”. The goal is to compute a min...

In microinjected Myxicola giant axons with elevated [Na]i, Na efflux was sensitive to Cao under some conditions. In Li seawater, sensitivity to Cao was high whereas in Na seawater, sensitivity to Cao was observed only upon elevation of [Ca]o above the normal value. In choline seawater, the sensitivity of Na efflux to Cao was less than that observed in Li seawater whereas Mg seawater failed to s...

This study examines the relative impact of canonical hypoxia-inducible factor-1alpha- (HIF-1α and Na+i/K+i-mediated signaling on transcriptomic changes evoked by hypoxia and glucose deprivation. Incubation of RASMC in ischemic conditions resulted in ∼3-fold elevation of [Na+]i and 2-fold reduction of [K+]i. Using global gene expression profiling we found that Na+,K+-ATPase inhibition by ouabain...

The involvement of potassium ions in the Na(+)-Ca2+ exchange process was studied in rat brain synaptic plasma membrane (SPM) vesicles. Addition of equimolar [K+] to the intravesicular and the extravesicular medium led to a stimulation of the Na+ gradient-dependent Ca2+ influx; this stimulation was noticeable already at 0.5 mM and reached its maximum at 2 mM K+. The magnitude of the K+ stimulati...

Microsomal sodium and potassium ion-stimulated adenosine triphosphatase ((Na+ + K+)-ATPase) was prepared from canine renal medulla by the method of Kyte. The two polypeptides of the enzyme were co-purified to homogeneity by solubilization with sodium cholate in the presence of egg lecithin and by removal of contaminating protein by sedimentation. This purified (Na+ + I(+)-ATPase was reconstitut...

thermal behavior of various solid feldspars are different, namely those of bivalent cations show no change in the distribution of al and si atoms, whereas feldspars of univalent cations become more disordered with raising temperature. in the latter case al atoms migrate from the sites they occupe at low temperatures and interchange positions with the si atoms. at high temperatures (but still be...