Transport of organic cations in brush border membrane vesicles from rabbit kidney cortex

1986 ◽  
Vol 407 (4) ◽  
pp. 404-408 ◽  
Author(s):  
C. Rafizadeh ◽  
M. Manganel ◽  
F. Roch-Ramel ◽  
C. Sch�li
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Rabbit Kidney ◽  
Organic Cations ◽  
Kidney Cortex

scholarly journals Studies on the orientation of brush-border membrane vesicles

1978 ◽  
Vol 172 (1) ◽  
pp. 57-62 ◽  
Author(s):  
W Haase ◽  
A Schäfer ◽  
H Murer ◽  
R Kinne
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Rat Kidney ◽  
Freeze Fracture ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Immunological Methods ◽  
Kidney Cortex ◽  
Asymmetric Distribution ◽  
Rat Kidney Cortex

Orientation of rat renal and intestinal brush-border membrane vesicles was studied with two independent methods: electron-microscopic freeze-fracture technique and immunological methods. With the freeze-fracture technique a distinct asymmetric distribution of particles on the two membrane fracture faces was demonstrated; this was used as a criterion for orientation of the isolated membrane vesicles. For the immunological approach the accessibility or inaccessibility of aminopeptidase M localized on the outer surface of the cell membrane to antibodies was used. With both methods we showed that the brush-border membrane vesicles isolated from rat kidney cortex and from rat small intestine for transport studies are predominantly orientated right-side out.

Nicotinic acid transport by brush border membrane vesicles from rabbit kidney

1981 ◽  
Vol 240 (3) ◽  
pp. F185-F191 ◽  
Author(s):  
E. F. Boumendil-Podevin ◽  
R. A. Podevin
Keyword(s):  
Membrane Potential ◽  
Nicotinic Acid ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Isonicotinic Acid ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Rabbit Kidney ◽  
Internal Space ◽  
Acid Uptake

The transport of nicotinic acid was investigated in brush border membrane vesicles isolated from rabbit kidney. The imposition of a Na+ gradient (out to in) induced a transient stimulation of nicotinic acid uptake above its final equilibrium value. This stimulation was specific for Na+. The uptake of nicotinic acid by the brush border membranes represented transport into an internal space and occurred in the absence of significant nicotinic acid degradation. The Na+ gradient-dependent uptake of nicotinic acid was saturable, apparent Km = 0.3 mM. Uptake of nicotinic acid was inhibited by its two isomers: picolinic and isonicotinic acid. In contrast, pyridine derivatives with two carboxyl groups or an amide group in addition to the carboxyl group were without inhibitory effect. Evaluation of changes in membrane potential using the lipophilic cation triphenylmethylphosphonium demonstrated that conditions that transiently generated either an interior-positive or an interior-negative membrane potential failed to affect the Na+-dependent transport of nicotinic acid. These findings provide evidence of the existence on the luminal membrane of a Na+ gradient-dependent and electroneutral transport system for nicotinic acid.

scholarly journals Sulphate-ion/sodium-ion co-transport by brush-border membrane vesicles isolated from rat kidney cortex

1979 ◽  
Vol 182 (1) ◽  
pp. 223-229 ◽  
Author(s):  
Heinrich Lücke ◽  
Gertraud Stange ◽  
Heini Murer
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Rat Kidney ◽  
Electrical Potential ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Kidney Cortex ◽  
Electrical Potential Difference ◽  
Univalent Cations ◽  
Rat Kidney Cortex

Uptake of SO42− into brush-border membrane vesicles isolated from rat kindey cortex by a Ca2+-precipitation method was investigated by using a rapid-filtration technique. Uptake of SO42− by the vesicles was osmotically sensitive and represented transport into an intra-vesicular space. Transport of SO42− by brush-border membranes was stimulated in the presence of Na+, compared with the presence of K+ or other univalent cations. A typical ‘overshoot’ phenomenon was observed in the presence of an NaCl gradient (100mm-Na+ outside/zero mm-Na+ inside). Radioactive-SO42− exchange was faster in the presence of Na+ than in the presence of K+. Addition of gramicidin-D, an ionophore for univalent cations, decreased the Na+-gradient-driven SO42− uptake. SO42− uptake was only saturable in the presence of Na+. Counter-transport of Na+-dependent SO42− transport was shown with MoO42− and S2O32−, but not with PO42−. Changing the electrical potential difference across the vesicle membrane by establishing different diffusion potentials (anion replacement; K+ gradient±valinomycin) was not able to alter Na+-dependent SO42− uptake. The experiments indicate the presence of an electroneutral Na+/SO42−-co-transport system in brush-border membrane vesicles isolated from rat kidney cortex.

scholarly journals Characterization of a sodium-dependent concentrative nucleobase-transport system in guinea-pig kidney cortex brush-border membrane vesicles

1994 ◽  
Vol 303 (3) ◽  
pp. 901-905 ◽  
Author(s):  
D A Griffith ◽  
S M Jarvis
Keyword(s):  
Guinea Pig ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Hill Coefficient ◽  
Kidney Cortex ◽  
Pig Kidney ◽  
Na Ions

The characteristics of hypoxanthine transport were examined in purified brush-border membrane vesicles isolated from guinea-pig kidney. Hypoxanthine uptake in the vesicles was specifically stimulated by both Na+ and an inside-negative potential, resulting in a transient accumulation of intravesicular hypoxanthine. Na(+)-dependent hypoxanthine influx was saturable (apparent Km 4.4 +/- 2.1 microM, Vmax. 128 +/- 29 pmol/min per mg of protein at 100 mM NaCl and 22 degrees C). Guanine, thymine, 5-fluorouracil and uracil inhibited hypoxanthine uptake (Ki values 1-30 microM), but adenine and the nucleosides inosine and thymidine were without effect. Guanine competitively inhibited Na(+)-dependent hypoxanthine influx, suggesting that it was a substrate for the active nucleobase transporter in guinea-pig renal membrane vesicles. A sigmoidal dependence between hypoxanthine influx and Na+ concentration was obtained (KNa 13 +/- 2 mM; Hill coefficient, h, 2.13 +/- 0.14), suggesting that at least two Na+ ions are transported per hypoxanthine molecule. This system differs from the Na(+)-nucleobase carrier in cultured LLC-PK1 renal cells, which has a stoichiometric coupling ratio of 1:1. These results represent the first demonstration of an active electrogenic nucleobase carrier in renal apical membrane vesicles.

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