Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Epithelial transport  (8)
  • Sulfate transport  (4)
  • Lactate  (3)
  • 2-Oxoglutarate  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Active sulfate reabsorption in the proximal convolution of the rat kidney: Specificity, Na+ and HCO 3 − dependence (1980)
    Springer
    Pflügers Archiv 383 (1980), S. 159-163 
    Details
    ISSN: 1432-2013
    Keywords: Renal tubule ; Sulfate transport ; Na+ coupled transport ; Thiosulfate ; Molybdate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using the standing droplet technique in the proximal convolution and simultaneous microperfusion of the peritubular capillaries, the decrease in luminal sulfate concentration with time and the zero net flux transtubular concentration difference of sulfate ( $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ ) at 45 s was determined — the latter being taken as a measure of the rate of active sulfate reabsorption. Starting with 0.5 mmol/l sulfate in both perfusates the $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ value of 0.35 mmol/l was approached exponentially with a half value time of 4.3 s. The $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ values in the early proximal and late proximal convolution did not deviate from each other. If the Na+ concentration in the perfusates was reduced, the $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ approached zero and extrapolated to a slightly negative value (c i〉c o). When 1 mmol/l ouabain was added to the perfusates $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ decreased by 66% (the latter experiments were performed in the golden hamster which is more sensitive to ouabain than the rat). 1 mmol/l thiosulfate diminished $$\Delta c_{{\text{SO}}_{\text{4}}^{{\text{2 - }}} } $$ by 68% and 1 mmol/l molybdate by 24%. Omitting or replacing bicarbonate by HEPES or glycodiazine reduced the sulfate reabsorption significantly, while acetazolamide (0.1 mmol/l) and increasing the CO2-pressure from 4.66 to 14.0 kPa (i.e. 5–15% CO2) had no effect. SITS 1 mmol/l had no effect on sulfate reabsorption. The data indicate that the sulfate reabsorption is driven by a Na+ gradient and inhibited by thiosulfate and molybdate, i.e. molecules which have a similar tetrahedral molecule structure. The sulfate reabsorption depends in an undefined manner on the presence of bicarbonate ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581877
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Bidirectional active transport of thiosulfate in the proximal convolution of the rat kidney (1980)
    Springer
    Pflügers Archiv 387 (1980), S. 127-132 
    Details
    ISSN: 1432-2013
    Keywords: Renal tubule ; Thiosulfate transport ; Na+ coupled transport ; Sulfate transport ; Paraaminohippurate transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using the standing droplet method in the late proximal convolution and simultaneous microperfusion of the peritubular capillaries, the zero net flux transtubular concentration difference of thiosulfate at 45 s was determined, the latter being taken as a measure of active thiosulfate transport. Under control conditions, in the presence of Na+, near zero Δc values were observed. When 1 mmol/l carinamide or paraaminohippurate (PAH) were added to the perfusates significant reabsorptive Δc arose. However, when 7.5 mmol/l sulfate was added to the Na+-free secretory Δc values were observed. Tested under Na+-free conditions, the secretory Δc was not influenced by simultaneously present 5 mmol/l of SO 4 2− but was diminished by 50 mmol/l SO 4 2− . PAH (1 mmol/l), carinamide (0.2 mmol/l) and probenecid (1 mmol/l) decreased the secretory Δc by 48, 65 and 48%, respectively. The PAH secretion was not influenced, when thiosulfate or sulfate up to 50 mmol/l was added to both perfusates. Under Na+-free conditions the Δc of thiosulfate in early loops of the proximal convolution is higher than in late loops, while for PAH this pattern is reversed. Taken together with the previously published inhibition of sulfate reabsorption by thiosulfate the data indicate 1. thiosulfate is reabsorved by the Na+-dependent sulfate transport system and 2. thiosulfate is simultaneously secreted by a carinamide-, probenecid-and PAH-sensitive secretory system. The secretory system might also be shared by sulfate. The thiosulfate net flux is the result of the difference in the activity of the counteracting transporters, located at the luminal and contraluminal cell side. Is is possible that the higher activity of the transporter at one cell side leads to a reversal of the flux through the transporter at the other cell side.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584263
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Contraluminal sulfate transport in the proximal tubule of the rat kidney (1985)
    Springer
    Pflügers Archiv 404 (1985), S. 307-310 
    Details
    ISSN: 1432-2013
    Keywords: Epithelial transport ; Contraluminal cell membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the specificity of the contraluminal sulfate transport system the inhibitory potency of salicylate analogs (5 mmol/l each) on the35SO 4 2− influx from the interstitium into cortical tubular cells in situ has been determined. The following was found: 2-hydroxybenzoate (salicylate), per se, did not inhibit contraluminal35SO 4 2− influx. The same holds when an additional NH2-group was introduced in position 4 or 5, or when an additional Cl-group was introduced in position 4. When an additional Cl- or NO2-group was introduced in position 5 a moderate inhibition was seen (app.K i≈4 mmol/l). However, introduction of 2 Cl- or 2 NO2-groups in position 3 and 5 creates compounds with strong inhibitory potency (app.K i≈0.5 mmol/l). 2-hydroxy-3,5-iodobenzoate inhibited too, but with a smaller inhibitory potency (app.K i≈2.3 mmol/l). 2-hydroxybenzoate analogs, which have a carboxy- or sulfo-group in position 5, exerted strong inhibition, those with a acetyl- or butyryl-group exerted moderate inhibition. 1-Naphthol-2-carboxylate did not inhibit, while 1-naphthol-4-sulfamoyl-2-carboxylate did. Amongst the dihydroxybenzoates, 2,3- and 2,5-dihydroxybenzoate did not inhibit contraluminal35SO 4 2− influx, while 2,4- and 2,6-dihydroxybenzoate did. The data indicate that a hydroxy-group in ortho-position and an electro-negative group in the meta-position to the carboxyl group and paraposition to the hydroxy-group are essential for interaction with the contraluminal sulfate transport system. The ability of 2,6-dihydroxybenzoate to inhibit might be explained by its ability to undergo mesomeric conformation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585340
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Contraluminal sulfate transport in the proximal tubule of the rat kidney (1985)
    Springer
    Pflügers Archiv 404 (1985), S. 300-306 
    Details
    ISSN: 1432-2013
    Keywords: Epithelial transport ; Contraluminal cell membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the specificity for the contraluminal sulfate transport system the inhibitory potency of disulfonates, di-, tricarboxylates and sulfocarboxylates on the35SO 4 2− influx from the interstitium into cortical tubular cells in situ has been determined. The following was found: 1) Methane- and ethane-disulfonate as well as benzene-1,3-disulfonate inhibit contraluminal35SO 4 2− influx (with an (app.K i of 〈6 mmol/l), while benzene-1,2- and 1,4-disulfonate do not. 2) The inhibitory potency of 1,3-benzene disulfonate is slightly augmented by an additional NH2 − or OH-group in position 4. However, OH-groups at position 4 and 5 or 4 and 6 abolish the inhibitory potency. 3) The naphthalene disulfonates tested inhibit only if they have an OH-group in ortho-position to one SO3H group. 4) The stilbene disulfonates H2DIDS and DNDS inhibit the contraluminal35SO 4 2− influx with high (app.K i≈0.8 mmol/l), DADS with lower potency (app.K i≈6 mmol/l). 5) Amongst the tested aliphatic di- and tricarboxylates inhibition was exerted by oxalate (app.K i 1.1 mmol/l) and maleate (app.K i 3.8 mmol/l), but not by malonate, hydroxymalonate and citrate. 6) Out of the tested benzenedicarboxylates only those inhibit which have the COO−-groups directly on the ring in 1,2 and 1,3 position (app.K i 4.0 and 2.7 mmol/l), but not in the 1,4 position. An additional OH-group in position 4 augments the inhibitory potency of 1,3 benzene-dicarboxylates (app.K i 0.8 mmol/l), while an OH group on position 5 abolishes it. 7) The benzene tricarboxylates (BTC) inhibit in the sequence 1,2,3-BTC〉1,3,5-BTC〉1,2,4-BTC (app.K i 0.9, 1.5 and 4.2 mmol/l, respectively). 8) The carboxy-benzene-sulfonates inhibit also in the 1,2 and 1,3 position only (app.K i 6.7 and 5 mmol/l), but not in the 1,4 position. Addition of an −OH-group to the 3-carboxy-1-benzene-sulfonate forming 4-hydroxy-3-carboxy-1-benzene-sulfate augments the inhibitory potency drastically (app.K i 0.32 mmol/l), while a NH2 substitution at the same position leaves it unchanged (app.K i 4.7 mmol/l). If, however, ethylamine instead of NH2 is used as substituent, the inhibitory potency is almost as high as of 4-hydroxy-3-carboxy-1-benzene-sulfonate (app.K i≈0.6 mmol/l). Amongst the dicarboxy-benzene-sulfonates, 3,4-carboxy-benzene-1-sulfonate inhibits (app.K i ca. 2 mmol/l), while 3,5-carboxy-benzene-1-sulfonate does not. The data indicate that a strong interaction of substrate with the sulfate transporter is given, when two charged groups (COO− and/or SO 3 − ) are present in a distance equivalent to the meta-position on the benzene ring and an additional hydrogen bond forming OH- or −NH-group. Hydrogen bond forming groups and charged groups in other positions usually abolish the inhibitory potency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585339
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Contraluminal sulfate transport in the proximal tubule of the rat kidney (1985)
    Springer
    Pflügers Archiv 404 (1985), S. 311-318 
    Details
    ISSN: 1432-2013
    Keywords: Epithelial transport ; Contraluminal cell membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to evaluate the specificity for the contraluminal sulfate transport system the inhibitory potency of phenol- and sulfonphthaleins, of sulfamoyl-compounds (diuretics) as well as diphenylamine-2-carboxylates (Cl− channel blockers) on the35SO 4 2− influx from the interstitium into cortical tubular cells in situ has been determined. The following was found: 1) Phenolsulfonphthalein (phenol-red) inhibited with an app.K i-value of 1.7 mmol/l, while analogs which had additional Br-atoms in position 3 and/or 5, i.e. bromphenol-blue, bromcresol-purple and bromcresol-green, inhibited with an apparentK i of 0.1 and 0.5 mmol/l respectively. 2) Phenolphthalein and tetrabromphenolphthalein did not inhibit, while the disulfonate dyes bromsulfalein, fuchsin acid and indigocarmine inhibited with aK i between ≈1 and 3 mmol/l. The highest inhibitory potency in this class of compounds was seen with orange G (app.K i 0.07 mmol/l). The monosulfonate dyes tested, fluoresceinsulfonate and orange I inhibited moderately with an app.K i of ≈5 mmol/l. 3) The 3-sulfamoyl compounds inhibited to a varying degree, when they had a neighbouring −NH-group (furylmethylamino-group), i.e. in position 6 to the COOH or SO3H-group, or when they had a phenoxy-group in position 4. 4) 4-sulfamoylbenzoate and the related compounds probenecid, acetazolamide and hydrochlorothiazide inhibited with an app.K i between 4 and 7 mmol/l. 5) All diphenylamine-2-carboxylate analogs inhibited with an app.K i between 3 and 5 mmol/l, even when the −NH-group was replaced by an =O-group or the benzene ring was replaced by a pyrimidine ring, but not when it was replaced by a thiophen ring. In contrast, 4-phenylaminepyridine-3-sulfonate was ineffective, while diphenylamine-2-amino sulfonate exerted the highest inhibition of this group with an app.K i of 1.4 mmol/l. When, however, the aminosulfonate group was replaced by a methylsulfonamide, the inhibitory potency disappeared. The data can be explained by inhibitory patterns found in previous papers for disulfonates [29], sulfonates with a hydrophobic moiety [28] or neighbouring OH-group [28, 29], carboxylates with a neighbouring −NH- or OH-group in position 2- and an electron-attracting group in position 5 [30].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585341
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Contraluminal transport of small aliphatic carboxylates in the proximal tubule of the rat kidney in situ (1986)
    Springer
    Pflügers Archiv 407 (1986), S. 488-492 
    Details
    ISSN: 1432-2013
    Keywords: Lactate ; Pyruvate ; 3-hydroxybutyrate ; Acetoacetate ; Nonspecific anion channel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the characteristic of contraluminal transport of hydrophylic small fatty acids the in situ stopped flow microperfusion technique [12] has been applied. By measuring with 4 s contact time the decrease in the contraluminal concentration of the respective radiolabelled substances the concentration dependence of the influx into the cortical cells was tested. The 4 s decrease in contraluminal concentration of chloroacetate,l-lactate,d-lactate, 3-hydroxybutyrate and acetoacetate was between 26% and 31%. For each substance the percent decrease was the same, no matter whether it was offered in a concentration of 0.1 or 10 mmol/l. Contraluminal disappearance of 0.1 mmol/ll-lactate was not influenced by 5 mmol/l H2DIDS, probenecid, phloretin, mersalyl or cyanocinnamate, but it was significantly (37%) inhibited by 5-nitro-2-(phenyl-propyl-amino) benzoate, a blocker of the nonspecific anion channel. The percent decrease in propionate uptake was somewhat larger — between 36% and 39% — but again not different at 0.01, 0.1, 1.0 and 10 mmol/l. With pyruvate the contraluminal decrease was 20% at 0.1 mmol/l and 31% at 10 mmol/l. The percent disappearance of the aromatic pyrazinoate was 38% and 34% at 0.1 and 10 mmol/l and for nicotinate 42% and 22%, respectively. The disappearance of nicotinate (0.1 mmol/l) was significantly inhibited by 10 mmol/l pyrazinoate and paraaminohippurate (PAH). The data are in agreement with the hypothesis that the hydrophilic small fatty acids traverse the contraluminal cell side by simple diffusion, possibly via the unspecific anion channel [14], pyruvate via the dicarboxylic acid pathway in a cooperative manner and pyrazinoate, as well as nicotinate, via the PAH pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00657505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Contraluminal para-aminohippurate (PAH) transport in the proximal tubule of the rat kidney (1987)
    Springer
    Pflügers Archiv 408 (1987), S. 38-45 
    Details
    ISSN: 1432-2013
    Keywords: Oxalate ; Succinate ; Glutarate ; 2-Oxoglutarate ; Citrate ; Sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the specificity for contraluminal para-aminohippurate (PAH) transport, the inhibitory potency of aliphatic dicarboxylates on3H-PAH influx, as well as the inhibitory effect on35SO 4 2− - and3H-succinate influx, from the interstitium into cortical tubular cells in situ has been determined. The following was found: 1. Testing a homologous series of dicarboxylates-ranging from the 2 C oxalate to the 10 C sebacate — PAH transport was inhibited by succinate (app.K i 1.35 mmol/l), and all longer dicarboxylates, with high potency (app.K i 0.05–0.35 mmol/l). Sulfate transport was inhibited only by oxalate (app.K i 1.1 mmol/l), while dicarboxylate transport was inhibited by succinate, glutarate, adipate and pimelate with decreasing potency (app.K i 0.04, 0.24, 0.91, 4.0 mmol/l, respectively). 2. PAH transport was inhibited by succinate and glutarate with high potency (app.K i 1.35 and 0.05 mmol/l), by the correspondent monomethylester to a lesser extent (app.K i 1.7 and 0.74 mmol/l), but not by the dimethylester. On the other hand, the semialdehyde of succinate with aK i-value of 1.2 mmol/l, had the same inhibitory potency as succinate itself, while the dialdehyde of glutarate (app.K i 1.4 mmol/l) was much less potent as glutarate. 3. Introduction of an oxo-, methyl- or sulfhydroxylgroup onto the 2-position of succinate, or of an oxo-group onto the 2-position of glutarate moderately augmented the inhibitory potency against PAH-uptake. However, introduction of a 2-hydroxy group onto succinate or glutarate in thel-position reduced the inhibitory potency more than in thed-position. Introduction of two methyl-, sulfhydryl- or hydroxyl-groups in the 2–3-position of succinate reduced or abolished its inhibitory potency. The introduction of a 2-amino group onto succinate or glutarate abolished its effect on PAH transport. However, N-acetylation or N-benzoylation led to a restitution in inhibitory potency. 4. The trans-isomers fumarate and mesaconate inhibited PAH- and methylsuccinate transport, while the cis-isomers maleate and citraconate did so to a lesser extent or not at all. The effect was reversed with the tricarboxylic aconitates, because cis-aconitate bears a CH2-extended COOH-group in trans-position and trans-aconitate in cis-position. The data indicate that there exist three different anion transport systems at the contraluminal cell side of the proximal renal tubule: 1. a sulfate-oxalate transporter, 2. a sodium-dependent dicarboxylate transporter, and 3. a paraaminohippurate transporter. The PAH transport system accepts dicarboxylates with chain length higher than 7.5 Å (=distance between the terminal oxygen atoms), while the dicarboxylate transport interacts with dicarboxylates with a chain length between 6.5 and 10 Å. Both transport systems prefer the transconfiguration. The effect of side groups on the interaction of dicarboxylates with the PAH-transport system is due mainly to hydrophobicity and electron configuration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581838
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Contraluminal phosphate transport in the proximal tubule of the rat kidney (1985)
    Springer
    Pflügers Archiv 405 (1985), S. S106 
    Details
    ISSN: 1432-2013
    Keywords: Epithelial transport ; Contraluminal cell membrane ; Dietary adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the characteristics of contraluminal phosphate transport the stopped flow microperfusion technique [13] has been applied. By measuring the time-dependent decrease of interstitial33Pi concentration at different starting concentrations a simple diffusion kinetics with a permeability coefficient of 7.5±1.0 · 10−8 cm2 s−1 was found. Such a kinetic was so far only observed with 2-deoxy-d-glucose. This substance, however, is transported in addition by facilitated diffusion as was seen by paraaminohippurate, methylsuccinate and sulfate. The contraluminal transport of phosphate was inhibited by H2-DIDS (5 mmol/l). It was, however, not influenced by omission of Na+ from the perfusates, by addition of sulfate (150 mmol/l), methylsuccinate (50 mmol/l), arsenate (50 mmol/l), the Hg-compound mersalyl (5 mmol/l), high and low phosphate diet and pH changes between 6.0 and 8.0. The data indicate that phosphate, which is reabsorbed from the lumen by a Na+-dependent transport system, leaves the cell by a rather unspecific contraluminal diffusion pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581789
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Reabsorption of monocarboxylic acids in the proximal tubule of the rat kidney (1982)
    Springer
    Pflügers Archiv 395 (1982), S. 212-219 
    Details
    ISSN: 1432-2013
    Keywords: SITS ; Probenecid ; Phloretin ; Acetazolamide ; Lactate ; Renal tubule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The transport ofd-lactate across the epithelium of the late proximal convolution was investigated by two methods: 1. by measuring the zero net flux transtubular concentration difference (Δc tt,45s) and the permeability (P) ofd-lactate and calculating from both the transtubular active transport rate (J lac act ). 2. By measuring the 3.5 s efflux ofd-lactate from the tubular lumen, while blood was flowing through the capillaries. The 3.5 s efflux comprises two components, one going through the brush border (J lac bb ) and one going the paracellular pathway (J lac paracell =P lac·c lac lumen). Both,J lac act andJ lac bb ofd-lactate gave the sameK m 1.9 and 1.7 mmol/l and the same maximal transport rate 3.2 and 2.9 pmol cm−1 s−1. TheK i ofl-lactate tested againstJ lac act andJ lac bb ofd-lactate was also the same: 1.1 and 1.0 mmol/l. These data indicate that under our experimental conditions only the flux through the brush border seems to be rate limiting and thatd-lactate uses the same transport system asl-lactate. When Na+ was omitted from the perfusatesJ lac act disappeared completely, whileJ lac bb was reduced by 64%. These data reflect the Na+ dependence of thed-lactate transport through the brush border. Variation of intra-and extracellular pH by raisingpCO2, omitting HCO 3 − from the perfusates or adding acetazolamide had no effect on the transport ofd-lactate when α-ketoglutarate was used as fuel. However, when acetate was used as fuel, intracellular acidosis brought the reducedJ lac act back to the values obtained with α-ketoglutarate as fuel. It is suggested that this is an effect on a contraluminal transport step. Probenecid (5 mmol/l) and phloretin (0.25 mmol/l) inhibitedJ lac act significantly.J lac bb , however, was only inhibited by probenecid when acetate was used as fuel. These data indicate that both compounds act on thed-lactate exit at the contraluminal cell side, but that probenecid acts in addition at the luminal cell side. SITS (1 mmol/l) augmentedJ lac bb when acetate was used as fuel and is similar to the effect of lowering intracellular pH as described above. The SH reagents mersalyl (1.0 mmol/l) and maleolylglycine (1 mmol/l) did not influenceJ lac bb .
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584812
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Contraluminal sulfate transport in the proximal tubule of the rat kidney (1985)
    Springer
    Pflügers Archiv 404 (1985), S. 293-299 
    Details
    ISSN: 1432-2013
    Keywords: Epithelial transport ; Contraluminal cell membrane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to study the specificity for the contraluminal sulfate transport system the inhibitory potency of sulfate esters and sulfonate compounds on the35SO 4 2− influx from the interstitium into cortical tubular cells in situ has been determined. The following was found: 1. From 10 sulfate monoesters tested 9 inhibited contraluminal sulfate influx with an app.K i between 0.6 and 6 mmol/l; the two sulfate diesters tested, however, did not. 2. Out of 8 aliphatic sulfonate compounds only three, having a NH- or OH-group in a suitable position, exerted a moderate inhibition (app.K i ca. 2–6 mmol/l). 3. Amongst 14 benzene sulfonates tested only 2 compounds (5-nitrobenzene-sulfonate and 2-hydroxy-5-nitrobenzenesulfonate) inhibited with aK i〈5 mmol/l. 4. Out of 10 naphthalene sulfonates tested 8 inhibited with aK i〈5; the highest inhibition was seen with the NH-containing 8-anilinonaphthalene-1-sulfonate (ANS), but no inhibition with 2 compounds containing an amino group. 5. From the polycyclic sulfonates pyrene-3-sulfonate and anthracene-1-sulfonate inhibited with aK i of approximately 2 mmol/l, while no inhibition was seen with anthracene-2-sulfonate. 6. Out of 4 amino-sulfonates tested benzene-1-amino-sulfonate and a similar benzyl-analog inhibited with aK i of 1 mmol/l and smaller; cyclohexyl-1-amino-sulfonate (cyclamate), however, inhibited only slightly (app.K i of 6 mmol/l). The data indicate that sulfate monoesters are well accepted by the contraluminal sulfate transport system. The affinity of sulfonate compounds to this system depends on neighbouring OH-groups −NH-groups, meta-positioned electronegative groups or a hydrophobic moiety in an appropriate position.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585338
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...