Inorganic anion transport in kidney and intestinal brush border and basolateral membranes

1980 ◽  
Vol 238 (6) ◽  
pp. F452-F460 ◽  
Author(s):  
S. Grinstein ◽  
R. J. Turner ◽  
M. Silverman ◽  
A. Rothstein
Keyword(s):  
Brush Border ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Anion Transport ◽  
Significant Inhibition ◽  
Kidney Cortex ◽  
Basolateral Membrane Vesicles ◽  
Inorganic Anion ◽  
Transport Pathways ◽  
Basolateral Membranes

The efflux of inorganic anions from purified brush border and basolateral membrane vesicles from dog kidney cortex was measured under equilibrium exchange conditions. Marked differences in temperature sensitivity and effects of inhibitors were found between the Cl and SO4 transport pathways and between the two types of membranes. SO4 transport in both brush border and basolateral membranes was markedly reduced by cooling, but significant inhibition by 4,4'–diisothiocyano-2,2'–disulfonic stilbene (DIDS) was only observed in basolateral vesicles. In contrast, Cl efflux from both types of vesicles was neither substantially inhibited by DIDS nor by lowering the temperature to 0 degrees C. Phosphate efflux from basolateral membrane vesicles was found to be only partially sensitive to DIDS. Attempts to label the stilbene-sensitive SO4 pathway in basolateral vesicles using [3H2]DIDS as a marker were unsuccessful due to the nonspecific labeling of many membrane components. The asymmetry in inorganic anion transport behavior exhibited by brush border and basolateral membrane vesicles from dog renal proximal tubule was also observed in equivalent vesicles prepared from rat small intestine.

Sensitivity of rat renal luminal and contraluminal sulfate transport systems to DIDS

1986 ◽  
Vol 250 (2) ◽  
pp. F226-F234 ◽  
Author(s):  
C. Bastlein ◽  
G. Burckhardt
Keyword(s):  
Transport System ◽  
Brush Border ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Transport Systems ◽  
Basolateral Membrane Vesicles ◽  
Sulfate Transport ◽  
Sulfate Uptake ◽  
Basolateral Membranes ◽  
Irreversible Inhibition

4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) was tested as an inhibitor of the sulfate transport systems in rat renal brush border and basolateral membrane vesicles. Na+-driven sulfate uptake into brush border membrane vesicles was half-maximally inhibited at 350 microM DIDS. Proton gradient-driven sulfate uptake into basolateral membrane vesicles was competitively inhibited by DIDS with a Ki of 2.4 microM. The Km for delta pH-driven sulfate uptake was 5.4 microM. The different affinities of the sulfate transport systems for DIDS correlated with different substrate specificities. The luminal transport system accepted a smaller range of anions than the contraluminal system and did not operate as a Na+-independent anion exchanger. After treatment of basolateral membrane vesicles with 50 microM DIDS at pH 8.4 for 30 min, an irreversible inhibition of sulfate uptake was observed. With brush border membranes, only a small irreversible inhibition was obtained. Lack of inhibition after treatment of basolateral membranes with DIDS at pH 6.4 indicated that DIDS reacted with deprotonated amino groups of the transport protein. Sulfate was protected from the irreversible inhibition by DIDS. Sodium-driven uptake of L-glutamate and methylsuccinate into basolateral membrane vesicles was not irreversibly inhibited by DIDS, indicating a specific action of DIDS on the contraluminal sulfate transport system. Irreversible and substrate-protectable inhibition of sulfate transport render DIDS suitable for future affinity labeling studies on the sulfate transport system in basolateral membranes.

Na+ gradient-dependent Pi uptake in basolateral membrane vesicles from dog kidney

1984 ◽  
Vol 246 (5) ◽  
pp. F663-F669 ◽  
Author(s):  
S. J. Schwab ◽  
S. Klahr ◽  
M. R. Hammerman
Keyword(s):  
Brush Border ◽  
Renal Cortex ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Basolateral Membrane Vesicles ◽  
Basolateral Membranes ◽  
Solute Uptake ◽  
Dog Kidney ◽  
Proximal Tubular

To ascertain whether Na+ gradient-stimulated 32Pi uptake was demonstrable in renal basolateral membrane vesicles, we measured 32Pi uptake in basolateral membrane suspensions isolated from canine renal cortex and compared solute uptake in basolateral suspensions with that measured in brush border suspensions. Measurements revealed Na+ gradient-dependent 32Pi transport in basolateral preparations. D-[3H] Glucose uptakes in basolateral suspensions were not stimulated by the Na+ gradient in contrast to findings in brush border suspensions. Na+ gradient-dependent 32Pi transport in basolateral suspensions was electrogenic in contrast to that measured in brush border preparations. Unlike 32Pi uptake in brush border preparations, Na+ gradient-dependent 32Pi uptake in basolateral suspensions did not increase as extravesicular pH was increased from 6.5 to 7.5. Na+ gradient-dependent 32Pi uptake in basolateral membranes showed saturation over the range of [Pi] from 5 to 100 microM (apparent Km, 14 +/- 2 microM; apparent Vmax, 34 +/- 2 pmol Pi X mg protein-1 X 30s-1). Our findings are compatible with the presence of an electrogenic Na+-Pi cotransporter in the canine proximal tubular basolateral membrane.

Fluidity of brush border and basolateral membranes from human kidney cortex

1983 ◽  
Vol 245 (2) ◽  
pp. F227-F231 ◽  
Author(s):  
C. Le Grimellec ◽  
S. Carriere ◽  
J. Cardinal ◽  
M. C. Giocondi
Keyword(s):  
Brush Border ◽  
Liquid Crystalline ◽  
Plasma Membranes ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Human Kidney ◽  
Kidney Cortex ◽  
Lipid Phase ◽  
Basolateral Membranes ◽  
Normal Human Kidney

The physical state of lipids in brush border and basolateral membrane vesicles prepared from normal human kidney cortex was investigated by fluorescence polarization and electron spin resonance. At physiologic temperature, lipids were significantly less ordered, i.e., more fluid, in basolateral than in brush border membranes. This difference was also observed using corresponding liposomes made from total lipid extracts. For both brush border and basolateral membranes, temperature-dependent experiments revealed the existence of a broad thermotropic transition extending approximately from 20 to 42 degrees C. These data are interpreted to indicate that plasma membranes from human kidney cortex function physiologically at the upper critical temperature of a transition that probably corresponds to a liquid crystalline-to-gel lipid phase separation.

scholarly journals Characterization of sodium-dependent and sodium-independent nucleoside transport systems in rabbit brush-border and basolateral plasma-membrane vesicles from the renal outer cortex

1989 ◽  
Vol 264 (1) ◽  
pp. 223-231 ◽  
Author(s):  
T C Williams ◽  
A J Doherty ◽  
D A Griffith ◽  
S M Jarvis
Keyword(s):  
Brush Border ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Nucleoside Transport ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Basolateral Membrane Vesicles ◽  
Plasma Membrane Vesicles ◽  
Outer Cortex ◽  
Overshoot Phenomenon

The transport of uridine into rabbit renal outer-cortical brush-border and basolateral membrane vesicles was compared at 22 degrees C. Uridine was taken up into an osmotically active space in the absence of metabolism for both types of membrane vesicles. Uridine influx by brush-border membrane vesicles was stimulated by Na+, and in the presence of inwardly directed gradients of Na+ a transient overshoot phenomenon was observed, indicating active transport. Kinetic analysis of the saturable Na+-dependent component of uridine flux indicated that it was consistent with Michaelis-Menten kinetics (Km 12 +/- 3 microM, Vmax. 3.9 +/- 0.9 pmol/s per mg of protein). The sodium:uridine coupling stoichiometry was found to be consistent with 1:1 and involved the net transfer of positive charge. In contrast, uridine influx by basolateral membrane vesicles was not dependent on the cation present and was inhibited by nitrobenzylthioinosine (NBMPR). NBMPR-sensitive uridine transport was saturable (Km 137 +/- 20 microM, Vmax. 5.2 +/- 0.6 pmol/s per mg of protein). Inhibition of uridine flux by NBMPR was associated with high-affinity binding of NBMPR to the basolateral membrane (Kd 0.74 +/- 0.46 nM). Binding of NBMPR to these sites was competitively blocked by adenosine and uridine. These results indicate that uridine crosses the brush-border surface of rabbit proximal renal tubule cells by Na+-dependent pathways, but permeates the basolateral surface by NBMPR-sensitive facilitated-diffusion carriers.

Urate transport in the proximal tubule: in vivo and vesicle studies

1985 ◽  
Vol 249 (6) ◽  
pp. F789-F798 ◽  
Author(s):  
A. M. Kahn ◽  
E. J. Weinman
Keyword(s):  
Proximal Tubule ◽  
Brush Border ◽  
Anion Exchanger ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Transport Processes ◽  
Basolateral Membrane Vesicles ◽  
Urate Transport ◽  
Rat Proximal Tubule

The transport of urate in the mammalian nephron is largely confined to the proximal tubule. Depending on the species, net reabsorption or net secretion is observed. The rat, like the human and the mongrel dog, demonstrates net reabsorption of urate and has been the most extensively studied species. The unidirectional reabsorption and secretion of urate in the rat proximal tubule occur via a passive and presumably paracellular route and by a mediated transcellular route. The reabsorption of urate, and possibly its secretion, can occur against an electrochemical gradient. A variety of drugs and other compounds affect the reabsorption and secretion of urate. The effects of these agents depend on their site of application (luminal or blood), concentration, and occasionally their participation in transport processes that do not have affinity for urate. Recent studies with renal brush border and basolateral membrane vesicles from the rat and brush border vesicles from the dog have determined the mechanisms for urate transport across the luminal and antiluminal membranes of the proximal tubule cell. Brush border membrane vesicles contain an anion exchanger with affinity for urate, hydroxyl ion, bicarbonate, chloride, lactate, p-aminohippurate (PAH), and a variety of other organic anions. Basolateral membrane vesicles contain an anion exchanger with affinity for urate and chloride but not for PAH. Both membrane vesicle preparations also permit urate translocation by simple diffusion. A model for the transcellular reabsorption and secretion of urate in the rat proximal tubule is proposed. This model is based on the vesicle studies, and it can potentially explain the majority of urate transport data obtained with in vivo techniques.

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