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...

A model of resting membrane electrogenesis in skeletal muscles of prepupal Calliphora erythrocephala was formulated. From experiments in which reversible effects of changing extracellular K and Na activities on the membrane potential (EM) were measured, three different values of a (the ratio of the partial permeabilities of the membrane to Na and K) were derived, each from a different range of ...

By using the isotope pairs (22)Na-(24)Na and (42)K-(86)Rb, the uptake and retention of Na and K was studied in the salt-tolerant Debaryomyces hansenii and in the less tolerant Saccharomyces cerevisiae at NaCl levels of 4 mm and 0.68, 1.35, and 2.7 m in the medium. The ratio of K to Na is much higher in the cells than in the media, and higher in D. hansenii than in S. cerevisiae under comparable...

In the lateral ocellus of the barnacle, we have tested the hypothesis that the transient increase of oxygen consumption (delta QO2) induced by light results from an increase in the rate of Na+ pumping. With a Na(+)-sensitive microelectrode, we measured the intracellular concentration of Na+ (Nai) in the photoreceptor cells. Nai was 17.6 +/- 1.2 mM (SE; n = 18) in darkness and it increased trans...

the effects of fish weight on salinity tolerance were studied in caspian salmon (salmo trutta caspius) parr. 180 fish (all with 2 years old but with three weights; 5, 15, 25g) were selected and they reared in freshwater (fw) and brackish water (bw; 13ppt salinity) for 10 days. the mrna expression of two α-subunit isoforms of na+, k+-atpase (α1a and α1b) and nkcc co-transporters were studied in ...

The steady-state voltage and [Na(+)](o) dependence of the electrogenic sodium pump was investigated in voltage-clamped internally dialyzed giant axons of the squid, Loligo pealei, under conditions that promote the backward-running mode (K(+)-free seawater; ATP- and Na(+)-free internal solution containing ADP and orthophosphate). The ratio of pump-mediated (42)K(+) efflux to reverse pump current...