Proton-lactate co transport in basolateral membrane vesicles from rat jejunum

1996 ◽  
Vol 16 (6) ◽  
pp. 521-527
Author(s):  
Maria Novella Orsenigo ◽  
Marisa Tosco ◽  
Umberto Laforenza ◽  
Alide Faelli
Keyword(s):  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Rat Jejunum ◽  
Basolateral Membrane Vesicles ◽  
Strong Inhibition ◽  
Lactate Transport ◽  
Basolateral Membranes ◽  
Lactate Uptake ◽  
Stimulation Of

Proton-coupled lactate transport across the basolateral membrane of rat jejunal enterocyte was studied using well purified membrane vesicles. L-lactate uptake is stimulated by an inwardly directed H+ gradient; the effect of the pH difference is drastically reduced by FCCP and by pCMBS; unlabelled L-lactate causes a strong inhibition, whilst furosemide is uneffective. The H+ gradient-dependent stimulation of L-lactate uptake is significantly inhibited also by SCN−: this finding could explain results recently reported in the literature in which H+-lactate symport was not evidenced in basolateral membranes from rat jejunum.

Bicarbonate uptake by basolateral membrane vesicles from rat jejunum

1983 ◽  
Vol 91 (5) ◽  
pp. 423-432
Author(s):  
A. Faelli ◽  
M. Tosco ◽  
M. N. Orsenigo ◽  
G. Esposito ◽  
V. Capraro
Keyword(s):  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Rat Jejunum ◽  
Basolateral Membrane Vesicles ◽  
Bicarbonate Uptake

Calbindin-D9k stimulates the calcium pump in rat enterocyte basolateral membranes

1989 ◽  
Vol 256 (1) ◽  
pp. G124-G128 ◽  
Author(s):  
J. R. Walters
Keyword(s):  
Vitamin D ◽  
Specific Activity ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Calcium Pump ◽  
Basolateral Membrane Vesicles ◽  
Calbindin D9k ◽  
Uptake Rates ◽  
Micromolar Range ◽  
Stimulation Of

Calbindin-D9k, a vitamin D-dependent Ca2+-binding protein, is closely associated with the transcellular absorption of calcium by mammalian enterocytes. Studies were performed to determine whether physiological concentrations of calbindin-D9k altered Ca2+ transport by the ATP-dependent Ca2+ pump in rat duodenal basolateral membrane vesicles. In solutions where free Ca2+ was buffered by EGTA, only a small stimulation of Ca2+ uptake rates could be demonstrated, and it was likely that this was secondary to changes in free Ca2+ concentration. However, a threefold stimulation of uptake by 30 microM calbindin-D9k was found when EGTA-free solutions were used, and changes in free Ca2+ activity or 45Ca2+ specific activity were avoided. The affinity for Ca2+ was reduced in this system but appeared to be stimulated by either calbindin-D9k or EGTA. Other Ca2+-binding proteins that bind Ca2+ in the micromolar range were found to increase Ca2+ uptake in the absence of EGTA. These experiments suggest that one of the actions of calbindin-D9k is to stimulate the rate of extrusion of Ca2+ from the enterocyte by increasing Ca2+ transport by the Ca2+ pump.

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.

scholarly journals Identification and isolation of the phosphorylated intermediate of the calcium pump in rat intestinal basolateral membranes

1988 ◽  
Vol 256 (2) ◽  
pp. 593-598 ◽  
Author(s):  
R Wajsman ◽  
J R F Walters ◽  
M M Weiser
Keyword(s):  
Vitamin D ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Calcium Pump ◽  
Basolateral Membrane Vesicles ◽  
Basolateral Membranes ◽  
Calmodulin Binding ◽  
Pump Activity ◽  
Acyl Phosphate ◽  
Crypt Cells

Transport of Ca2+ by the ATP-dependent Ca2+ pump has been demonstrated previously in rat intestinal basolateral-membrane vesicles. To identify the Ca2+-pump protein, duodenal basolateral membranes were phosphorylated with [gamma-32P]ATP in the presence of Ca2+ and La3+, under conditions conducive for maximal formation of the phosphorylated intermediate of the Ca2+ pump. Four major phosphoprotein bands were seen on autoradiograms of acidic SDS/polyacrylamide gels; the properties of a phosphoprotein (pp) at 130 kDa (pp130) were consistent with those expected for the plasma-membrane Ca2+ pump. This phosphoprotein was markedly enhanced by La3+, exhibited the characteristics of an acyl-phosphate bond, was preferentially phosphorylated from ATP and inhibited by micromolar concentrations of vanadate. Another phosphoprotein of 115 kDa possibly represented the endoplasmic reticulum Ca2+ pump or a fragment of pp130. Other phosphoproteins of 75 and 95 kDa were predominantly expressions of alkaline phosphatase. Formation of pp130 was highest in duodenal basolateral-membrane preparations when compared with those of jejunum and ileum or other subcellular fractions. A similar correlation between Ca2+-pump activity and pp130 formation was not found in membranes from villus-tip and crypt cells or in vitamin D-deficient animals. pp130 was isolated as a single phosphoprotein by calmodulin-affinity chromatography. We conclude that pp130 represents the phosphorylated intermediate of the rat intestinal basolateral-membrane Ca2+ pump, which can be separated from other phosphoproteins using its properties as a calmodulin-binding protein.

Indirect Na+ dependency of urate and p-aminohippurate transport in pig basolateral membrane vesicles

1991 ◽  
Vol 261 (2) ◽  
pp. F265-F272 ◽  
Author(s):  
D. Werner ◽  
F. Roch-Ramel
Keyword(s):  
Proximal Tubule ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Organic Anions ◽  
Transport Processes ◽  
Basolateral Membrane Vesicles ◽  
Pig Kidney ◽  
Different Characteristics ◽  
Stimulation Of

Membrane vesicles were used to study the basolateral transport of urate and p-aminohippurate (PAH) in the proximal tubule of the pig kidney. Consistent with a cooperation between a Na(+)-2-oxoglutarate cotransporter and a 2-oxoglutarate-urate or a 2-oxoglutarate-PAH exchanger, urate and PAH uptakes were stimulated in presence of extravesicular 2-oxoglutarate when an inwardly directed Na+ gradient was applied. Both transports exhibited, however, different characteristics. The optimal 2-oxoglutarate concentration for stimulating uptakes was 10 microM for PAH and 150 microM for urate. Extravesicular chloride was required to observe a stimulation of PAH uptake but not of urate uptake. Transports of both PAH and urate exhibited different affinity sequences for various organic anions. Stimulated PAH uptake was inhibited by probenecid greater than cold PAH greater than urate = pyrazinoate greater than lactate, whereas stimulated urate uptake was inhibited by probenecid greater than cold urate greater than PAH and not by pyrazinoate or lactate. These results are consistent with independent transport processes for urate and PAH in pig basolateral membrane vesicles, both being indirectly driven by an inwardly directed Na+ gradient.

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.

Bicarbonate movement across basolateral membrane vesicles from rat jejunum

1984 ◽  
Vol 401 (4) ◽  
pp. 427-429
Author(s):  
A. Faelli ◽  
M. Tosco ◽  
M. N. Orsenigo ◽  
G. Esposito ◽  
V. Capraro
Keyword(s):  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Rat Jejunum ◽  
Basolateral Membrane Vesicles

Basolateral tetraethylammonium transport in intact tubules: specificity and trans-stimulation

1991 ◽  
Vol 261 (3) ◽  
pp. F386-F392 ◽  
Author(s):  
W. H. Dantzler ◽  
S. H. Wright ◽  
V. Chatsudthipong ◽  
O. H. Brokl
Keyword(s):  
Organic Cation ◽  
Basolateral Membrane ◽  
Physiological Role ◽  
Membrane Vesicles ◽  
Cation Transport ◽  
Organic Cations ◽  
Basolateral Membrane Vesicles ◽  
Bathing Medium ◽  
First Time ◽  
Stimulation Of

To examine the specificity of proximal renal basolateral organic cation transport, the effects of unlabeled organic cation substrates in the bathing medium on the rate of uptake [14C]tetraethylammonium ([14C]TEA) by intact nonperfused proximal tubules and isolated basolateral membrane vesicles (BLMV) from rabbit kidneys were explored. The pattern of inhibition of transport by a battery of unlabeled organic cations was similar in intact tubules and BLMV. To determine if trans-stimulation could be demonstrated across the basolateral membrane of intact tubules, the effects of preloading tubules with unlabeled substrates on the rate of uptake of [14C]TEA and the effects of unlabeled substrates in the bathing medium on the rate of efflux of [14C]TEA from tubules preloaded with this labeled substrate were examined. Trans-stimulation was clearly demonstrated for the first time in intact tubules. However, of the compounds that significantly inhibited [14C]TEA uptake (TEA, amiloride, tetrapropylammonium, mepiperphenidol, isopropyl pyridinium, and choline), only TEA itself and choline produced a trans-stimulation of [14C]TEA uptake. Moreover, choline appeared to be at least as effective as TEA itself as a counter ion for TEA transport. Such trans-stimulation could play a physiological role in the net reabsorption of choline and the net secretion of most other organic cations.

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