Considering the key role of renal dopamine in tubular sodium handling, we hypothesized that c-type natriuretic peptide (CNP) and Ang-(1-7) may regulate renal dopamine availability in tubular cells, contributing to Na(+), K(+)-ATPase inhibition. Present results show that CNP did not affect either (3)H-dopamine uptake in renal tissue or Na(+), K(+)-ATPase activity; meanwhile, Ang-(1-7) was able t...

Because plants grow under many different types of soil and environmental conditions, we investigated the hypothesis that multiple pathways for K+ uptake exist in plants. We have identified a new family of potassium transporters from Arabidopsis by searching for homologous sequences among the expressed sequence tags of the GenBank database. The deduced amino acid sequences of AtKUP (for Arabidop...

The rate and extent of Cu2+ uptake by rat liver mitochondria was measured under various conditions. 1. The uptake is both greater and faster without an energy supply. 2. The uptake, when occuring in ionic media, has a biphasic character, that is it always slows down after an initial burst, and then re-accelerates. 3. Uptake of Cu2+ in the presence of energy initiates K+ uptake from K+-containin...

Infarct size and brain edema following ischemia/reperfusion are reduced by inhibitors of the Na+, K+, 2Cl-, and water cotransporter NKCC1 and by β1-adrenoceptor antagonists. NKCC1 is a secondary active transporter, mainly localized in astrocytes, driven by transmembrane Na+/K+ gradients generated by the Na+,K+-ATPase. The astrocytic Na+,K+-ATPase is stimulated by small increases in extracellula...

This research aimed to determine the effect and best granular KCl fertilizer dosage in increasing K-available, K-Uptake, yield of sweet corn (Zea mays saccharata Sturt.) Talenta variety on Inceptisols from Jatinangor. The method used was a randomized completely block design (RCBD) with nine treatments three replications. treatment consists without fertilization as control (A; N, P, K (B); ¼ + P...

Cells of Bacillus acidocaldarius that were grown with 2.7 mM K+ expressed a low-affinity K+ uptake system. The following observations indicate that its properties closely resemble those of the Escherichia coli Trk and Streptococcus faecalis KtrI systems: (i) the B. acidocaldarius system took up K+ with a Km of 1 mM; (ii) it accepted Rb+ (Km of 6 mM; same Vmax as for K+); (iii) it was still acti...

Frog erythrocytes were incubated in iso- or hypotonic media containing 10 mmol/l Rb+ and 0.1 mmol/l ouabain and both Rb+ uptake and K+ loss were measured simultaneously. Rb+ uptake by frog red cells in iso- and hypotonic media was reduced by 30-60% in the presence of 0.01-0.1 mmol/l [(dihydroindenyl)oxy] alkanoic acid (DIOA) or 0.5-1.0 mmol/l furosemide. Furosemide inhibited K+ loss from frog e...

Potassium uptake rate of two cotton (Gossypium hirsutum L.) varieties viz., NIBGE-2 and MNH-786 was investigated in nutrient solution culture having deficient K @ 0.3 mM and deficient K+ Na @ 0.3 +2.7 mM. Depletion of K from solution was monitored over a period of 24 h at regular time intervals after 0, 0.5, 1.0, 1.5, 2, 3, 4, 5, 6, 8, 10, 12 and 24 h to estimate K uptake kinetics of the roots ...

Net uptake of potassium by low K, high Na cells of Neurospora at pH 5.8 is accompanied by net extrusion of sodium and hydrogen ions. The amount of potassium taken up by the cells is matched by the sum of sodium and hydrogen ions lost, under a variety of conditions: prolonged preincubation, partial respiratory inhibition (DNP), and lowered [K](o). All three fluxes are exponential with time and o...

PURPOSE To determine the stoichiometry of Na+,K+,Cl- cotransport in fetal human nonpigmented ciliary epithelial cells and the effect of forskolin, an adenylyl cyclase activator, on Na+,K+,Cl- cotransport. METHODS 86Rb+ as a marker for K+ was used to study ouabain-insensitive, bumetanide-sensitive 86Rb+ uptake in cultured human nonpigmented epithelial (NPE) monolayers. RESULTS The dependence...