Na+/HCO3-co-transport in basolateral membrane vesicles isolated from rabbit renal cortex.

Grassl, Steven M.; Aronson, Peter S.

doi:10.1016/s0021-9258(19)84448-4

Cited by 176 publications

(13 citation statements)

References 25 publications

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“…Studies on intact epithelia provided evidence for the existence of an electrogenic cotransport mechanism for sodium and bicarbonate in basolateral membranes of proximal tubular epithelial cells of rats and rabbits (Yoshitomi et al, 1985;Sasaki et al, 1985;Alpern & Chambers, 1986;Alpern, 1985); a direct documentation of this transport mechanism became recently available for isolated rabbit proximal tubular basolateral membranes (Grassl & Aronson, 1986;Akiba et al, 1986). The present report extends these observations and documents the existence of a sodium-bicarbonate cotransport mechanism also for the isolated rat proximal tuRbular basolateral membrane.…”

Section: Discussionmentioning

confidence: 99%

“…Studies on intact proximal tubular preparations of the tiger salamander (Boron & Boulepaep, 1983), rats (Yoshitomi et al, 1985) and rabbits (Sasaki et al, 1985) provided evidence for a coupling between sodium and bicarbonate fluxes in the basolateral membrane of the epithelial cell. Recently, studies on rabbit renal cortical basolateral membranes identified a bicarbonate-sodium cotransport mechanism with a stoichiometry of 3 (Grassl & Aronson, 1986;Akiba et al, 1986). Until now such studies have not been performed in intact small intestinal epithelia or on membrane vesicles isolated thereof.…”

Section: Introductionmentioning

confidence: 99%

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Sodium-bicarbonate cotransport occurs in rat kidney cortical membranes but not in rat small intestinal basolateral membranes

Hagenbuch

Stange

Murer

1987

Biochemical Journal

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Basolateral membrane vesicles were isolated from rat kidney cortex and small intestinal enterocytes. Both membrane preparations show ATP-dependent calcium uptake and cytochalasin B-sensitive D-glucose transport. In renal membranes, sodium influx is stimulated by bicarbonate; bicarbonate-dependent sodium flux is membrane-potential-dependent and inhibited by 4,4'-di-isothiocyanato-2, 2'-stilbenedisulphanic acid ('DIDS'). Small intestinal basolateral membranes do not show bicarbonate-dependent sodium fluxes.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Sodium-bicarbonate cotransport occurs in rat kidney cortical membranes but not in rat small intestinal basolateral membranes

Hagenbuch

Stange

Murer

1987

Biochemical Journal

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“…Grassl and Aronson showed that in the presence of CO 2 /HCO 3 Ϫ buffer and port. In kidney proximal tubule cells, this transporter mediates the exit of HCO 3 Ϫ from the cell to the blood in the absence of an initial HCO 3 Ϫ gradient, Na ϩ influx was stimulated in BLM vesicles when an inside positive [5][6][7][8], whereas in other epithelial cells and certain nonepithelial cells such as heart [14,15] and liver [10,11], this membrane potential was imposed using an inward K ϩ gradient and the K ϩ ionophore valinomycin [20]. These transporter mediates the entry of HCO 3 Ϫ from blood to the cell.…”

Section: Ionic Base Speciesmentioning

confidence: 99%

“…The acidic or alkaline pH i [45,46]. This is in contrast with the half-maximal inhibitor concentration (IC50) for DIDS pH i sensitivity of the other HCO 3 Ϫ extruding pathway, was approximately 200 mol/L [20], whereas for DNDS, namely the Cl Ϫ /HCO 3 Ϫ exchanger. This latter exchanger it was approximately 400 mol/L [8].…”

Section: Inhibitor Profilementioning

confidence: 99%

Physiologic and molecular aspects of the Na+:HCO3- cotransporter in health and disease processes

Soleimani

Burnham

2000

Kidney International

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Approximately 80% of the filtered load of HCO3- is reabsorbed in the proximal tubule via a process of active acid secretion by the luminal membrane. The major mechanism for the transport of HCO3- across the basolateral membrane is via the electrogenic Na+:3HCO3- cotransporter (NBC). Recent molecular cloning experiments have identified the existence of three NBC isoforms (NBC-1, NBC-2, and NBC-3).1 Functional and molecular studies indicate the presence of all three NBC isoforms in the kidney. All are presumed to mediate the cotransport of Na+ and HCO3- under normal conditions and may be functionally altered in certain pathophysiologic states. Specifically, NBC-1 may be up-regulated in metabolic acidosis and potassium depletion and in response to glucocorticoid excess and may be down-regulated in response to HCO3- loading or alkalosis. Recent studies provide molecular evidence indicating the expression of NBC-1 in pancreatic duct cells. NBC is activated by cystic fibrosis transmembrane conductance regulator (CFTR) and plays an important role in HCO3- secretion in the agonist-stimulated state in pancreatic duct cells. The purpose of this review is to summarize recent functional and molecular studies on the regulation of NBCs in physiologic and pathophysiologic states. Possible signals responsible for the regulation of NBCs in these conditions are examined. Furthermore, the possible role of this transporter in acid-base disorders (such as proximal renal tubular acidosis) is discussed.

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“…Basolateral membrane vesicles were enriched from rabbit kidney cortex by Percoll density fractionation as described by Grassl and Aronson. 52 Briefly, kidney cortex (5 g) was initially homogenized with Tekmar TK10 homogenizer in 4 Â (weight/volume) ice-cold hepes-buffered sucrose with EDTA (HBE) (10 mM N-2-hydroxyethylpiperazine-N 0 -2-ethanesulphonic acid, 250 mM sucrose pH 7.6, supplemented with Complete R Protease Inhibitor tablets) and then Dounce homogenized (30 strokes). Homogenates were clarified by centrifugation at 2500 Â g for 15 min at 41C.…”

Section: Fractionation Of Membrane Vesicles Isolated From Kidney Cortexmentioning

confidence: 99%

Basolateral carbonic anhydrase IV in the proximal tubule is a glycosylphosphatidylinositol-anchored protein

Purkerson

Kittelberger

Schwartz

2007

Kidney International

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Carbonic anhydrase (CA) IV facilitates HCO(3) reabsorption in the renal proximal tubule by catalyzing the reversible hydration of CO(2). CAIV is tethered to cell membranes via a glycosylphosphatidylinositol (GPI) lipid anchor. As there is basolateral as well as apical CAIV staining in proximal tubule, the molecular identity of basolateral CAIV was examined. Biotinylation of confluent monolayers of rat inner medullary collecting duct cells stably transfected with rabbit CAIV showed apical and basolateral CAIV, and in the cell transfectants expressing high levels of CAIV, a transmembrane form was targeted to the basolateral membrane. Basolateral expression of CAIV ( approximately 46 kDa) was confirmed in normal kidney tissue by Western blotting of vesicle fractions enriched for basolateral membranes by Percoll density fractionation. We examined the mode of membrane linkage of basolaterally expressed CAIV in the kidney cortex. CAIV detected in basolateral or apical membrane vesicles exhibited similar molecular size by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis following deglycosylation, and was equally sensitive to phosphatidylinositol-specific phospholipase C digestion, indicating that CAIV is expressed on the basolateral membrane as a GPI-anchored protein. Half of the hydratase activity of basolateral vesicles was resistant to SDS denaturation, compatible with being CAIV. Thus, GPI-anchored CAIV resides in the basolateral membrane of proximal tubule epithelia where it may facilitate HCO(3) reabsorption via association with kNBC1.

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Na+/HCO3-co-transport in basolateral membrane vesicles isolated from rabbit renal cortex.

Cited by 176 publications

References 25 publications

Sodium-bicarbonate cotransport occurs in rat kidney cortical membranes but not in rat small intestinal basolateral membranes

Sodium-bicarbonate cotransport occurs in rat kidney cortical membranes but not in rat small intestinal basolateral membranes

Physiologic and molecular aspects of the Na+:HCO3- cotransporter in health and disease processes

Basolateral carbonic anhydrase IV in the proximal tubule is a glycosylphosphatidylinositol-anchored protein

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