Cystine-glutamate transport interactions in rat renal cortical tubules, brushborder vesicles, and cultured renal tubule cells

1986 ◽  
Vol 6 (1) ◽  
pp. 113-119 ◽  
Author(s):  
John W. Foreman ◽  
Pamela D. McNamara ◽  
Margaret Ann Bowring ◽  
Judithann Lee ◽  
Claire Rea ◽  
...  
Keyword(s):  
Renal Tubule ◽  
Membrane Vesicles ◽  
Glutamate Transport ◽  
Serum Free ◽  
Defined Media ◽  
Tubule Cells ◽  
Isolated Rat

Glutamate had no significant effect on the uptake of 0.025 mM cystine by isolated rat renal cortical tubules and brushborder membrane vesicles in contrast to lysine which significantly inhibits cystine transport. Glutamate, however, markedly inhibited cystine uptake by rat renal tubule cells grown in a serum-free, hormonally defined media for 5 days. Lysine also inhibited cystine transport in these cultured renal tubule cells.

Effect of cystine loading and cystine dimethylester on renal brushborder membrane transport

1990 ◽  
Vol 10 (5) ◽  
pp. 455-459 ◽  
Author(s):  
John W. Foreman ◽  
Linda Benson
Keyword(s):  
Membrane Transport ◽  
Renal Tubule ◽  
Membrane Vesicles ◽  
Maximal Rate ◽  
Cystine Dimethylester ◽  
Tubule Cells

The effect of loading renal tubule cells with cystine was studied by incubating them with cystine dimethylester. Proline uptake into brushborder membrane vesicles isolated from the cystine loaded cells was not different from that observed into brushborder vesicles isolated from tubules incubated in buffer alone. Incubating brushborder membranes with 2 mM cystine dimethylester for 10 minutes reduced the uptake of proline by 27% after 15 seconds of incubation and by 21% after 60 seconds of incubation. There was no effect after 20 minutes of incubation. Pre-incubating brushborder membrane vesicles with cystine dimethylester had no statistically significant effect on the affinity of priline for the carrier, but did reduce the maximal rate of proline uptake by 49%.

scholarly journals Metabolic studies of rat renal tubule cells loaded with cystine: the cystine dimethylester model of cystinosis.

1995 ◽  
Vol 6 (2) ◽  
pp. 269-272
Author(s):  
J W Foreman ◽  
L L Benson ◽  
M Wellons ◽  
E D Avner ◽  
W Sweeney ◽  
...  
Keyword(s):  
Fanconi Syndrome ◽  
Renal Tubule ◽  
Renal Tissue ◽  
Renal Tubules ◽  
O2 Consumption ◽  
Metabolic Disturbances ◽  
Tissue Homogenates ◽  
Cystine Dimethylester ◽  
Tubule Cells ◽  
Isolated Rat

The cause of Fanconi syndrome in cystinosis is enigmatic. It has previously been shown that renal tubules could be loaded with cystine by incubating them with cystine dimethylester (CDE), mimicking the biochemical hallmark of cystinosis. Such tubules have impaired transport, decreased whole-cell O2 consumption, and substrate utilization. In this study, the metabolic disturbances in cystine-loaded renal tubule cells were further characterized. Isolated rat renal tubules were loaded with cystine by incubating them with 2 mM CDE for 10 min. This had no significant effect on total ATPase, Na(+)-K(+)-ATPase, or the ouabain-insensitive ATPase activity of renal tissue homogenates from these cystine-loaded tubules. Intracellular K was significantly lower in the cystine-loaded tubules (37 +/- 2 versus 47 +/- 3 nEq/mg; P < 0.008). Intracellular ATP was reduced by 39% in the cystine-loaded tubules (23.7 +/- 2.4 versus 38.1 +/- 3.3 nmol/mg of protein; P < 0.0025). CDE (2 mM) reduced isolated mitochondrial O2 consumption with glutamate as the substrate by 66% (4.7 +/- 0.7 versus 13.9 +/- 0.8 nm/min per mg of protein, P < 0.001) but had no effect on mitochondrial O2 consumption with succinate as the substrate. It was speculated that the impaired transport from cystine loading with CDE is secondary to a decrease in energy generation.

PRIMARY CULTURES OF HUMAN PROXIMAL TUBULE CELLS (HPTC) IN SERUM FREE DEFINED MEDIA: A CHARACTERIZATION STUDY

1992 ◽  
pp. 12-14
Author(s):  
Françoise Courjault ◽  
Jacques Chevalier ◽  
Danielle Leroy ◽  
Dominique K. Chopin ◽  
Clément C. Abbou ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Primary Cultures ◽  
Proximal Tubule Cells ◽  
Serum Free ◽  
Defined Media ◽  
Characterization Study ◽  
Tubule Cells ◽  
Human Proximal Tubule

scholarly journals Therapeutic concentrations of cyclosporine A, but not FK506, increase P-glycoprotein expression in endothelial and renal tubule cells

1998 ◽  
Vol 54 (4) ◽  
pp. 1139-1149 ◽  
Author(s):  
Ingeborg A. Hauser ◽  
Michael Koziolek ◽  
Ulrich Hopfer ◽  
Frank Thévenod
Keyword(s):  
Cyclosporine A ◽  
Renal Tubule ◽  
P Glycoprotein ◽  
Tubule Cells

Reversed polarity of Na(+) -K(+) -ATPase: mislocation to apical plasma membranes in polycystic kidney disease epithelia

1991 ◽  
Vol 260 (3) ◽  
pp. F420-F430 ◽  
Author(s):  
P. D. Wilson ◽  
A. C. Sherwood ◽  
K. Palla ◽  
J. Du ◽  
R. Watson ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Polycystic Kidney Disease ◽  
Plasma Membranes ◽  
Renal Tubule ◽  
Apical Membrane ◽  
Membrane Vesicles ◽  
Renal Tubules ◽  
Polycystic Kidney ◽  
Permeable Membrane ◽  
Reversed Polarity

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder in which renal tubules become enormously enlarged due to fluid accumulation. Na(+) -K(+) -ATPase was compared in normal and cystic regions of whole kidneys and in confluent primary cultures of microdissected renal tubule and cyst-lining epithelia. Immunostaining with antibodies directed against the Na(+) -K(+) -ATPase catalytic alpha-subunit was confined to apical, luminal plasma membranes of ADPKD epithelia, which was a complete reversal of the normal renal tubule polarized location in basolateral membranes. Mislocated Na(+) -K(+) -ATPase was shown to be functionally active, because identical intense apical staining was observed by use of a cytochemical assay. In addition, biochemical assays showed a significant increase in these ouabain-inhibitable Na(+) -K(+) -ATPase specific activity levels in ADPKD kidneys compared with age-matched normal kidneys. Specific binding of [3H] ouabain was not only increased but also confined to the apical membrane vesicles prepared from cystic regions of ADPKD kidneys compared with normal age-matched controls, in which binding was confined to basolateral membrane vesicles. Although steady-state levels of Na(+) -K(+) -ATPase alpha- and beta-subunit in mRNAs were increased somewhat in ADPKD kidneys, this alone was not sufficient to account for the observed activation. Confluent ADPKD epithelia grown on dual-chamber, permeable membrane supports also showed reversed polarity of 22NaCl vectorial transport, because this was from basal to apical media compartments. Because this transport could also be blocked by ouabain, this suggested apical Na(+) -K(+) -ATPase was responsible and implicated altered polarity of Na(+) -K(+) -ATPase and resultant Na+ secretion as a mechanism for cyst formation in ADPKD. Because no reversal of polarity of other basolateral or apical membrane proteins was detected, an intracellular sorting defect specific for Na(+) -K(+) -ATPase is proposed.

Na,K-ATPase Activity in Renal Tubule Cells From Milan Hypertensive Rats

1989 ◽  
Vol 2 (7) ◽  
pp. 563-566 ◽  
Author(s):  
Maria-Luisa Melzi ◽  
Alejandro Bertorello ◽  
Yutaka Fukuda ◽  
Ingrid Muldin ◽  
Fabio Sereni ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Renal Tubule ◽  
Hypertensive Rats ◽  
Tubule Cells
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