Effect of para-chloromercuribenzenesulfonic acid and temperature on cell water osmotic permeability of proximal straight tubules

Whittembury, Guillermo; Carpi–Medina, Paola; González, E.; Linares, Henry

doi:10.1016/0005-2736(84)90192-5

Cited by 58 publications

(31 citation statements)

References 19 publications

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“…Our values for P/in BLMV are similar to Pf estimated in the proximal tubule basolateral membrane (after division by the folding factor of 36 [41]) measured by a rapid video recording technique (0.011 cm/sec [15,42,43]). …”

Section: Discussionsupporting

confidence: 82%

Evidence for water channels in renal proximal tubule cell membranes

Meyer

Verkman

1987

J. Membrain Biol.

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Water transport mechanisms in rabbit proximal convoluted cell membranes were examined by measurement of: osmotic (Pf) and diffusional (Pd) water permeabilities, inhibition of Pf by mercurials, and activation energies (Ea) for Pf. Pf was measured in PCT brush border (BBMV) and basolateral membrane (BLMV) vesicles, and in viable PCT cells by stopped-flow light scattering; Pd was measured in PCT cells by proton NMR T1 relaxation times using Mn as a paramagnetic quencher. In BLMV, Pf (0.019 cm/sec, 23 degrees C) was inhibited 65% by 5 mM pCMBS and 75% by 300 microM HgCl2 (KI = 42 microM); Ea increased from 3.6 to 7.6 kcal/mole (15-40 degrees C) with 300 microM HgCl2. In BBMV, Pf (0.073 cm/sec, 23 degrees C, Ea = 2.8 kcal/mole, less than 33 degrees C and 13.7 kcal/mole, greater than 33 degrees C) was inhibited 65% with HgCl2 with Ea = 9.4 kcal/mole (15-45 degrees C). Mercurial inhibition in BLMV and BBMV was reversed with 10 microM mercaptoethanol. Viable PCT cells were isolated from renal cortex by Dounce homogenization and differential seiving. Impedence sizing studies show that PCT cells are perfect osmometers (100-1000 mOsm). Assuming a cell surface-to-volume ratio of 25,000 cm-1, Pf was 0.010 +/- 0.002 cm/sec (37 degrees C) and Pd was 0.0032 cm/sec. Pf was independent of osmotic gradient size (25-1000 mOsm) with Ea 2.5 kcal/mole (less than 27 degrees C) and 12.7 kcal/mole (greater than 27 degrees C). Cell Pf was inhibited 53% by 300 microM HgCl2 (23 degrees C) with Ea 6.2 kcal/mole. These findings indicate that cell Pf is not restricted by extracellular or cytoplasmic unstirred layers and that cell Pf is not flow-dependent. The high BLMV and BBMV Pf, inhibition by HgCl2, low Ea which increases with inhibition, and the measured Pf/Pd greater than 1 in cells in the absence of unstirred layers provide strong evidence for the existence of water channels in proximal tubule brush border and basolateral membranes. These channels are similar to those found in erythrocytes and are likely required for rapid PCT transcellular water flow.

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Section: Discussionsupporting

confidence: 82%

Evidence for water channels in renal proximal tubule cell membranes

Meyer

Verkman

1987

J. Membrain Biol.

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“…Here we test this hypothesis by treating internodal cells of Nitellopsis obtusa with various inhibitors of protein function. Using the sulfhydryl inhibitor, chtoromercuriphenyl sulfonic acid (p CMPS), which inhibits water movement in animal cells (Naccache & Sha'afi, 1974;Brown et al, 1975;Benga et al, 1983Benga et al, , 1987Benga et al, , 1989Lukacovic, Toon & Solomon, 1984;Whittembury et al, 1984;Fischbarg, Liebovitch & Koniarek, 1987), we show that a sulfhydryl-containing protein serves as an aqueous channel for exosmosis. In addition, using nonyltriethylammonium (C9), we show that a K + channel serves as an aqueous channel for endosmosis.…”

Section: Introductionmentioning

confidence: 99%

Nature of the water channels in the internodal cells ofNitellopsis

Wayne

Tazawa

1990

J. Membrain Biol.

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The hydraulic resistance was measured on internodal cells of Nitellopsis obtusa using the method of transcellular osmosis. The hydraulic resistance was approximately 2.65 pm-1 sec Pa, which corresponds to an osmotic permeability of 101.75 microns sec-1 (at 20 degrees C). p-Chloromercuriphenyl sulfonic acid (pCMPS) (0.1-1 mM, 60 min) reversibly increases the hydraulic resistance in a concentration-dependent manner. pCMPS does not have any effect on the cellular osmotic pressure. pCMPS increases the activation energy of water movement from 16.84 to 32.64 kJ mol-1, indicating that it inhibits water movement by modifying a low resistance pathway. pCMPS specifically increases the hydraulic resistance to exosmosis, but does not influence endosmosis. By contrast, nonyltriethylammonium (C9), a blocking agent of K+ channels, increases the hydraulic resistance to endosmosis, but does not affect that to exosmosis. These data support the hypothesis that water moves through membrane proteins in characean internodal cells and further that the polarity of water movement may be a consequence of the differential gating of membrane proteins on the endo- and exoosmotic ends.

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“…In the present studies we reasoned that if we could block water uptake into the cells, we should be able to block elongation. To test this, we exposed stimulated cells to 1.0 p M pCMBS, an inhibitor of osmotic water channels (Whittembury et al, 1984). Elongation was prevented by this drug (Table 11, supporting an important role for water influx in the elongation phenomenon.…”

Section: Discussionmentioning

confidence: 97%

Decreased membrane permeability to potassium is responsible for the cell volume increase that drives lens fiber cell elongation

Parmelee

Beebe

1988

Journal Cellular Physiology

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Differentiation of lens epithelial cells into fiber cells involves an increase in cell volume which previously was proposed to be the direct cause of the extensive cell elongation which accompanies fiber formation. In this study we have continued to investigate the mechanism underlying cell elongation by defining the minimum nutrient and ion requirements of elongating cells, measuring potassium and sodium fluxes in stimulated and unstimulated lens epithelia, and determining the effects of several pharmacological agents on elongation and ion transport. We have shown that elongation will occur in a basic salt/glucose solution with Insulin-like growth factor I/somatomedin-C stimulation. Neither sodium nor any metabolite appears to be the osmotically active species which drives the increase in cell volume. However, potassium efflux rate coefficient was 47% lower in differentiating cells than in unstimulated cells, whereas potassium uptake rates and ouabain effects were similar. Cells did not elongate in potassium-free medium nor in the presence of several drugs which prevent the accumulation of intracellular potassium or hinder osmotic water flux. Unstimulated cells elongated, however, with the application of quinidine, a drug known to block potassium channels. We propose that stimulation of lens epithelial cells with an insulin-like growth factor signals the closure of a certain population of potassium channels. As a result, potassium efflux from the differentiating cells slows while active potassium uptake continues at a constant rate. Potassium then accumulates within the cell causing water influx, an increase in cell volume, and cell elongation.

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Effect of para-chloromercuribenzenesulfonic acid and temperature on cell water osmotic permeability of proximal straight tubules

Cited by 58 publications

References 19 publications

Evidence for water channels in renal proximal tubule cell membranes

Evidence for water channels in renal proximal tubule cell membranes

Nature of the water channels in the internodal cells ofNitellopsis

Decreased membrane permeability to potassium is responsible for the cell volume increase that drives lens fiber cell elongation

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