Brush-border processes and transepithelial Na and Cl transport by rabbit ileum

Nellans, Hugh N.; Ra, Frizzell; Schultz, SG

doi:10.1152/ajplegacy.1974.226.5.1131

Cited by 119 publications

(52 citation statements)

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“…(D) Effects of replacement of either Ringer Na+ or Cl-on theophyllinedependent changes in ion fluxes When Ringer Cl-is replaced isosmotically by sulphate, or when Ringer Na+ is replaced isosmotically by choline, it is observed here, as previously (Nellans et al 1973(Nellans et al , 1974, that there is no theophylline-dependent change in either the unidirectional or net flux of Na+ or Cl-respectively (Table 3). In sulphate media, no significant effects of theophylline upon the isotope ratio R of Na+ are apparent (Table 4).…”

Section: Ion Secretion By Rabbit Ileumsupporting

confidence: 82%

“…Thereafter, tissues in the presence of choleragen show an increased shortcircuit current whereas in control the current continues to fall in this same period. The delay in action of choleragen is similar to that described previously (Field et al 1972) and contrasts with the rapid onset of theophylline action (Nellans et al 1974). Flux measurements in experiments involving choleragen were commenced 80 min after the start of incubation following a 20 min preincubation period of the isotope.…”

Section: Ion Secretion By Rabbit Ileumsupporting

confidence: 73%

“…It is considered that theophylline and choleragen-induced secretion results from a neutral NaCl secretary process which may be triggered by raised intracellular levels of cyclic AMP (Powell, Binder & Curran, 1972 Nellans, Frizzell & Schultz, 1973, 1974. However, Nellans et al (1973Nellans et al ( , 1974 consider that net secretion of NaCl also arises from an inhibition by cyclicAMP of a brushborder influx pathway for NaCl.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, Powell et al (1973) and Nellans et al (1973Nellans et al ( , 1974 have shown that the reduction in net Na+ absorption is equal to the change in net Cl-flux following addition of theophylline. This 1: 1 stoichiometry in the theophylline-dependent change in Na+ and Cl-net movements, whilst being compatible with Field's view that Cl-is actively secreted, is more consistent with the view that the secretary process is neutral.…”

Section: Introductionmentioning

confidence: 99%

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The effects of theophylline and choleragen on sodium and chloride ion movements within isolated rabbit ileum.

Naftalin¹,

Simmons²

1979

The Journal of Physiology

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SUMMARY1. Theophylline (10 mM) and choleragen change the direction of net Cl-movements across rabbit ileum, in the short-circuit current condition, from absorption to secretion. The specific activity ratio R of C1-tracers within the tissue coming from mucosal and serosal solutions respectively is increased, which is consistent with an increase in Cl-exchange flux across the mucosal border.2. Net Na+ movement is also changed from net absorption to secretion by theophylline and choleragen; the specific activity ratio R of Na+ tracers is raised by theophylline. Because of the large paracellular component to transepithelial Na+ movements, an increase in Na+ exchange flux across the mucosal border is not detected.3. 2,4,6-Triaminopyrimidine (20 mM) which has been previously shown to block paracellular Na+ movements, blocks both the theophylline and choleragen-dependent reversal of net Na+ movement by preventing the decrease in m-s Na flux. The theophylline-dependent increase in the ratio R of Na+ is still present, and is consistent with an increase in Na+ exchange flux across the mucosal border -unmasked by removal of the paracellular flux components. 4. Ouabain (0.1 mM) abolishes net absorption of Na+ and Cl-in control and net secretion of Na+ and Cl-in theophylline-treated tissue. Ouabain does not affect the theophylline-dependent increase in Cl-exchange across the mucosal border.5. Replacement of Ringer Cl-with SO'-or Na+ by choline prevents the effects of theophylline and choleragen on Na+ and C1-fluxes respectively.6. Ethacrynate (0 1 mM) prevents the theophylline-dependent effects on net Na+ movement. Raising ethacrynate to 0-2 mm abolishes the effects of theophylline on Cl-exchange.An interpretation of these results is that theophylline and choleragen raise the Cl-permeability of the brush border. This increases NaCl leakage from the hypertonic lateral intercellular space into the mucosal solution thereby causing secretion. The selective action of triaminopyrimidine and ethacrynate (0.1 mM) on Na+ flux indicates that Na+ and Cl-move via separate transport pathways across the mucosal border.

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Section: Ion Secretion By Rabbit Ileumsupporting

confidence: 82%

Section: Ion Secretion By Rabbit Ileumsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The effects of theophylline and choleragen on sodium and chloride ion movements within isolated rabbit ileum.

Naftalin¹,

Simmons²

1979

The Journal of Physiology

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“…Salt and water movement across the ileal mucosa is thought to occur actively through transcellular mechanisms and passively through paracellular pathways. Originally, sodium and chloride absorption in the ileum was thought to be coupled [3,4], but more recent studies show that this process involves simultaneous sodium/hydrogen ion and chloride/bicarbonate exchange [5]. Electrolyte transport through the intestinal mucosa is reportedly responsible for the metabolic change.…”

Section: Introductionmentioning

confidence: 99%

Changes in sodium transport in epithelial cells in a rat ileal‐augmented bladder model

et al. 2002

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Objective To investigate changes in the morphology and sodium transport ability of intestinal epithelium diverted to the urinary tract, using an in vitro sodiumbinding benzofuran isophthalate (SBFI) technique, as the effects of long-term urine exposure on the transport of electrolytes through intestine are incompletely understood. Materials and methods Ileal augmentation cystoplasty was conducted in female Sprague-Dawley rats; at 3 and 12 months after surgery the serum concentration of sodium, chloride and potassium were measured. Sodium transport in the ileal epithelial cells diverted to the urinary tract was evaluated using SBFI, as the value of the 340/380 nm excitation ratio measured with fluorescence spectrophotometry. The villous height and the number of villi per ileal length were obtained from haematoxylin and eosin-stained sections. Results After 3 months the mean ( SD ) serum sodium concentrations in normal and augmented rats were 140.4 (2.5) and 140.7 (3.5) mmol/L, respectively; the chloride concentration in normal rats was 97.0 (2.9), and in augmented rats at 3 and 12 months it was 102.4 (2.9) and 99.0 (3.7) mmol/L, respectively. At 3 months, chloride concentrations were significantly higher in augmented than in normal rats ( P < 0.05). The mean ( SD ) 340/380 nm ratio increased by 0.85 (0.09) in the normal ileum, and by 0.73 (0.15) and 0.49 (0.23) in the ileum of augmented rats at 3 and 12 months, respectively; the difference between normal and augmented ileum at 12 months was significant ( P < 0.05). At 12 months the villous height in the augmented ileum, at 227.6 (16.0) m m, was significantly less than in the normal ileum, at 803.4 (66.2) m m ( P < 0.05). However, the number of villi/mm ileum in normal and augmented rats at 12 months was 13.7 (1.5) and 15.0 (0.8), respectively, and not significantly different. Conclusion Sodium transport decreased significantly after long-term exposure to urine; the improvement in metabolic change was probably attributable to alterations of electrolyte transport and atrophic changes of the villus.

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Ion-Coupled Transport across Biological Membranes

Schultz

1978

Physiology of Membrane Disorders

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Brush-border processes and transepithelial Na and Cl transport by rabbit ileum

Cited by 119 publications

References 0 publications

The effects of theophylline and choleragen on sodium and chloride ion movements within isolated rabbit ileum.

The effects of theophylline and choleragen on sodium and chloride ion movements within isolated rabbit ileum.

Changes in sodium transport in epithelial cells in a rat ileal‐augmented bladder model

Ion-Coupled Transport across Biological Membranes

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