Thyroid hormone stimulation of Na/Pi-cotransport in opossum kidney cells

1995 ◽  
Vol 431 (2) ◽  
pp. 266-271 ◽  
Author(s):  
Victor Sorribas ◽  
Daniel Markovich ◽  
Tiziano Verri ◽  
J�rg Biber ◽  
Heini Murer
Keyword(s):  
Thyroid Hormone ◽  
Kidney Cells ◽  
Opossum Kidney ◽  
Hormone Stimulation ◽  
Opossum Kidney Cells ◽  
Stimulation Of

scholarly journals Insulin-induced Stimulation of Na+,K+-ATPase Activity in Kidney Proximal Tubule Cells Depends on Phosphorylation of the α-Subunit at Tyr-10

1999 ◽  
Vol 10 (9) ◽  
pp. 2847-2859 ◽  
Author(s):  
Eric Féraille ◽  
Maria Luisa Carranza ◽  
Sandrine Gonin ◽  
Pascal Béguin ◽  
Carlos Pedemonte ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Tyrosine Phosphorylation ◽  
Site Directed Mutagenesis ◽  
Common Mechanism ◽  
Sodium Reabsorption ◽  
Kidney Cells ◽  
Α Subunit ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Stimulation Of

Phosphorylation of the α-subunit of Na+,K+-ATPase plays an important role in the regulation of this pump. Recent studies suggest that insulin, known to increase solute and fluid reabsorption in mammalian proximal convoluted tubule (PCT), is stimulating Na+,K+-ATPase activity through the tyrosine phosphorylation process. This study was therefore undertaken to evaluate the role of tyrosine phosphorylation of the Na+,K+-ATPase α-subunit in the action of insulin. In rat PCT, insulin and orthovanadate (a tyrosine phosphatase inhibitor) increased tyrosine phosphorylation level of the α-subunit more than twofold. Their effects were not additive, suggesting a common mechanism of action. Insulin-induced tyrosine phosphorylation was prevented by genistein, a tyrosine kinase inhibitor. The site of tyrosine phosphorylation was identified on Tyr-10 by controlled trypsinolysis in rat PCTs and by site-directed mutagenesis in opossum kidney cells transfected with rat α-subunit. The functional relevance of Tyr-10 phosphorylation was assessed by 1) the abolition of insulin-induced stimulation of the ouabain-sensitive86Rb uptake in opossum kidney cells expressing mutant rat α1-subunits wherein tyrosine was replaced by alanine or glutamine; and 2) the similarity of the time course and dose dependency of the insulin-induced increase in ouabain-sensitive 86Rb uptake and tyrosine phosphorylation. These findings indicate that phosphorylation of the Na+,K+-ATPase α-subunit at Tyr-10 likely participates in the physiological control of sodium reabsorption in PCT.

scholarly journals Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells

2016 ◽  
Vol 310 (3) ◽  
pp. C227-C232 ◽  
Author(s):  
Katherine J. Massey ◽  
Quanwen Li ◽  
Noreen F. Rossi ◽  
Susan M. Keezer ◽  
Raymond R. Mattingly ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Rat Kidney ◽  
Proximal Tubules ◽  
Kidney Cells ◽  
Ang Ii ◽  
Wild Type ◽  
Stimulate Activity ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Stimulation Of

How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser938 were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K·mg protein−1·min−1 and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser938 is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells.

scholarly journals Ouabain-insensitive acidification by dopamine in renal OK cells: primary control of the Na+/H+exchanger

2001 ◽  
Vol 281 (1) ◽  
pp. R10-R18 ◽  
Author(s):  
Pedro Gomes ◽  
M. A. Vieira-Coelho ◽  
P. Soares-da-Silva
Keyword(s):  
Adenylyl Cyclase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Kidney Cells ◽  
Primary Control ◽  
Intracellular Acidification ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Stimulation Of

The present study was aimed at evaluating the role of D1- and D2-like receptors and investigating whether inhibition of Na+ transepithelial flux by dopamine is primarily dependent on inhibition of the apical Na+/H+ exchanger, inhibition of the basolateral Na+-K+-ATPase, or both. The data presented here show that opossum kidney cells are endowed with D1- and D2-like receptors, the activation of the former, but not the latter, accompanied by stimulation of adenylyl cyclase (EC50 = 220 ± 2 nM), marked intracellular acidification (IC50 = 58 ± 2 nM), and attenuation of amphotericin B-induced decreases in short-circuit current (28.6 ± 4.5% reduction) without affecting intracellular pH recovery after CO2 removal. These results agree with the view that dopamine, through the activation of D1- but not D2-like receptors, inhibits both the Na+/H+ exchanger (0.001933 ± 0.000121 vs. 0.000887 ± 0.000073 pH unit/s) and Na+-K+-ATPase without interfering with the Na+-independent HCO[Formula: see text] transporter. It is concluded that dopamine, through the action of D1-like receptors, inhibits both the Na+/H+ exchanger and Na+-K+-ATPase, but its marked acidifying effects result from inhibition of the Na+/H+exchanger only, without interfering with the Na+-independent HCO[Formula: see text] transporter and Na+-K+-ATPase.

Stimulation of Na+/H+ exchange activity by endothelin in opossum kidney cells

1995 ◽  
Vol 430 (1) ◽  
pp. 137-144 ◽  
Author(s):  
R. Walter ◽  
C. Helmle-Kolb ◽  
J. Forgo ◽  
U. Binswanger ◽  
H. Murer
Keyword(s):  
Kidney Cells ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Stimulation Of ◽  
Exchange Activity

NMR-visible intracellular P(i) and phosphoesters during regulation of Na(+)-P(i) cotransport in opossum kidney cells

1994 ◽  
Vol 267 (4) ◽  
pp. C915-C919 ◽  
Author(s):  
M. Barac-Nieto ◽  
A. Spitzer
Keyword(s):  
Brush Border Membrane ◽  
Maximum Velocity ◽  
Membrane Vesicles ◽  
Kidney Cells ◽  
Opossum Kidney ◽  
Ok Cells ◽  
Opossum Kidney Cells ◽  
Igf I ◽  
Stimulation Of

There is an inverse relationship between intracellular concentration of P(i) ([P(i)]i) in the kidney and maximum velocity (Vmax) of Na(+)-P(i) cotransport in brush-border membrane vesicles both in P(i)-deprived and growing animals. However, at any given [P(i)]i, the Vmax is substantially higher in growing than in P(i)-deprived animals. This suggests that growth and P(i) depletion act on P(i) transport via different mechanisms. We tested this hypothesis by measuring the nuclear magnetic resonance-visible phosphate and the Vmax of Na(+)-P(i) cotransport in proximal tubule-like cells [opossum kidney (OK) cells] cultured in vitro. OK cells incubated in 1 mM extracellular P(i) had a [P(i)]i of 1.1 +/- 0.2 mM and a P(i) uptake of 1.47 +/- 0.06 nmol/mg in 5 min. Exposure of OK cells to P(i)-free medium decreased [P(i)]i by 80 +/- 7% (P < 0.01) and stimulated P(i) transport by 34 +/- 7% (P < 0.05). Exposure of OK cells to 10(-8) M insulin-like growth factor I (IGF-I) increased P(i) transport by 25 +/- 8% (P < 0.05) but did not affect [P(i)]i. The stimulation of Vmax produced by IGF-I was additive to that due to P(i) restriction. In addition, P(i) deprivation decreased the phosphomonoesters by 0.66 +/- 0.04-fold (P < 0.05) and increased the phosphodiesters by 2.5 +/- 0.5-fold (P < 0.01). Treatment with IGF-I increased both the phosphomonoesters (1.2 +/- 0.1-fold) and the phosphodiesters (4.1 +/- 0.6-fold). These results support the assumption that low P(i) supply and IGF-I stimulate Na(+)-P(i) cotransport by independent mechanisms.

D2-like receptor-mediated inhibition of Na+-K+-ATPase activity is dependent on the opening of K+ channels

2002 ◽  
Vol 283 (1) ◽  
pp. F114-F123 ◽  
Author(s):  
Pedro Gomes ◽  
P. Soares-da-Silva
Keyword(s):  
Protein Kinase ◽  
Atpase Activity ◽  
Receptor Activation ◽  
Inhibitory Effect ◽  
Skf 38393 ◽  
Kidney Cells ◽  
Dependent Manner ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Stimulation Of

This study examined the effects of D2-like dopamine receptor activation on Na+-K+-ATPase activity while apical-to-basal, ouabain-sensitive, amphotericin B-induced increases in short-circuit current and basolateral K+ ( I K) currents in opossum kidney cells were measured. The inhibitory effect of dopamine on Na+-K+-ATPase activity was completely abolished by either D1- or D2-like receptor antagonists and mimicked by D1- and D2-like receptor agonists SKF-38393 and quinerolane, respectively. Blockade of basolateral K+ channels with BaCl2 (1 mM) or glibenclamide (10 μM), but not apamin (1 μM), totally prevented the inhibitory effects of quinerolane. The K+ channel opener pinacidil decreased Na+-K+-ATPase activity. The inhibitory effect of quinerolane on Na+-K+- ATPase activity was abolished by pretreatment of opossum kidney cells with pertussis toxin (PTX). Quinerolane increased I K across the basolateral membrane in a concentration-dependent manner; this effect was abolished by pretreatment with PTX, S-sulpiride, and glibenclamide. SKF-38393 did not change I K. Both H-89 (protein kinase A inhibitor) and chelerythrine (protein kinase C inhibitor) failed to prevent the stimulatory effect of quinerolane on I K. The stimulation of the D2-like receptor was associated with a rapid hyperpolarizing effect, whereas D1-like receptor activation was accompanied by increases in cell membrane potential. It is concluded that stimulation of D2-like receptors leads to inhibition of Na+-K+-ATPase activity and hyperpolarization; both effects are associated with the opening of K+channels.

Action of EGF and PGE2 on basolateral organic anion uptake in rabbit proximal renal tubules and hOAT1 expressed in human kidney epithelial cells

2004 ◽  
Vol 286 (4) ◽  
pp. F774-F783 ◽  
Author(s):  
C. Sauvant ◽  
D. Hesse ◽  
H. Holzinger ◽  
K. K. Evans ◽  
W. H. Dantzler ◽  
...  
Keyword(s):  
Cell Line ◽  
Ex Vivo ◽  
Organic Anion ◽  
Renal Tubules ◽  
Proximal Tubule Cell ◽  
Kidney Cells ◽  
Opossum Kidney ◽  
Opossum Kidney Cells ◽  
Anion Uptake ◽  
Stimulation Of

We recently showed that, in a proximal tubule cell line (opossum kidney cells), epithelial growth factor (EGF) stimulates basolateral organic anion transport (OAT) via ERK1/2, arachidonic acid, phospholipase A2, and generation of prostaglandins. PGE2 binds the prostanoid receptor and, thus, activates adenylate cyclase and PKA, which stimulate basolateral organic anion uptake. In the present study, we investigated whether this regulatory cascade is also true 1) for ex vivo conditions in isolated renal proximal (S2) tubules from rabbit and 2) in a human renal epithelial cell line stably expressing human OAT1 (IHKE-hOAT1). EGF activated ERK1/2 in S2 tubules and IHKE-hOAT1, and, in both cases, inhibition of ERK activation (by U-0126) abolished this stimulation. In S2 tubules and IHKE-hOAT1, EGF led to an increase of organic anion uptake, which again was inhibited by U-0126. PGE2 stimulated basolateral organic anion uptake in rabbit S2 tubules and IHKE-hOAT1. EGF- and PGE2-mediated stimulation of organic anion uptake was abolished by inhibition of PKA in rabbit S2 tubules and IHKE-hOAT1, respectively. We conclude that 1) stimulation of basolateral organic anion uptake by EGF or PGE2 is a widespread (if not general) regulatory mechanism, 2) the signal transduction pathway involved seems to be general, 3) stimulation of basolateral organic anion uptake by EGF or PGE2 is also present under ex vivo conditions and, thus, is not a cell culture artifact, 4) activation of OAT1 is sufficient to explain the stimulatory effects of EGF and PGE2 in opossum kidney cells and rabbit S2 segments, and 5) stimulation of basolateral OAT1 by EGF or PGE2 is also important in humans and, thus, may have clinical implications.

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