Effect of acetazolamide on sodium and chloride transport by in vitro rabbit ileum

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

doi:10.1152/ajplegacy.1975.228.6.1808

Cited by 59 publications

(16 citation statements)

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“…We have previously presented evidence that a coupled NaCl influx process is present in colonic mucosa of the rat (33), and the parallel decreases in Ja and Jcl are consistent with inhibition of coupled NaCl influx. In the rabbit ileum and gallbladder coupled NaCl influx processes have been established and can be inhibited by cyclic AMP (34)(35)(36). These present findings and those in both the ileum and gallbladder are very similar.…”

Section: Discussionsupporting

confidence: 86%

Ricinoleic acid stimulation of active anion secretion in colonic mucosa of the rat.

Racusen¹,

Binder²

1979

J. Clin. Invest.

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A B S T R A C T Perfusion of the colon with ricinoleic acid produces fluid and electrolyte accumulation. The mechanism of these changes in water and electrolyte movement is unknown. These studies were designed to determine whether ricinoleic acid affects active ion transport across isolated rat colonic mucosa. 0.5 mM Na ricinoleate produced significant increases in potential difference (3.8+0.5 mV) and short-circuit currenit (ISC) (99.2±+10.1 jiA/cm2). The increases in IS, produced by Na ricinoleate were inhibited by both removal of bicarbonate and chloride and by the presence of theophylline. The hydroxy fatty acid also resulted in a significant decrease in net Na absorption from 4.7+0.8 to 0.1+0.7 ueq/h cm2 and reversed net Cl transport from absorption (+4.5±0.9) to secretion (-2.2+0.8 ,ueq/h cm2). In parallel studies 0.5 mM Na riciinoleate increased mucosal cyclic AMP content by 58%. The concentrations of Na ricinoleate required to produce detectable and maximal increases in both ISc and cyclic ANIP were the same. These results provide evidence in support of the concept that hydroxy fatty acid-induced fluid and electrolyte accumulation is driven by an active ion secretory process.

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Section: Discussionsupporting

confidence: 86%

Ricinoleic acid stimulation of active anion secretion in colonic mucosa of the rat.

Racusen¹,

Binder²

1979

J. Clin. Invest.

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“…Removal of chloride from the incubation saline did not influence the fluxes of sodium, indicating that the process responsible for the net transmural movement of sodium did not include a step which coupled the movements of sodium and chloride analogous to the mechanisms described in studies on gall-bladder and intestine (Frizzell, Koch & Schultz, 1976;Nellans, Frizzell & Schultz, 1975).…”

Section: Sodium Transportmentioning

confidence: 85%

Transport of sodium and chloride across rat gastric mucosa in vitro.

Jackson¹,

Norris²

1985

The Journal of Physiology

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The effects of ion substitution, inhibitors and variations in transmural p.d. on the movements of sodium and chloride across an in vitro preparation of rat gastric mucosa have been studied. The tissue maintained net steady‐state transport of sodium in the mucosal‐to‐serosal direction in the absence of transmural gradients of electrochemical potential. Sodium transport was independent of the presence of chloride, and was abolished by 1 X 10(‐5) M‐amiloride. The inhibitor produced a decrease in short‐circuit current equivalent to the depression of sodium transport, indicating that the sodium transport process was electrogenic. Variations in transmural p.d. showed that the sodium transport process included two components: one that varied with p.d. and one that was independent of it. These findings have been interpreted in terms of a system for sodium transport composed of three components: two rate‐limiting entry mechanisms at the apical membrane, one of which can be represented as a conductive channel for sodium diffusion and the other as a neutral process possibly a sodium‐hydrogen exchanger, and a voltage‐independent pump at the basolateral membrane analogous to the constant‐current pump models described in some other epithelia. The tissue maintained a net secretory movement of chloride in the short‐circuited condition. The process responsible for net transport of chloride could be resolved into two components: one that was sodium dependent, electrogenic, and abolished by 8 X 10(‐3) M‐acetazolamide, and one that was independent of the presence of sodium, electrically silent and abolished by 5 X 10(‐4) M‐SITS (4‐acetamido‐4'‐isothiocyano‐2,2'‐disulphonic acid stilbene). Both components of the chloride transport process varied with p.d. These findings were interpreted in terms of a system of three components: two entry mechanisms at the basolateral membrane including a coupled sodium‐chloride influx process and a chloride‐bicarbonate exchanger in parallel, and a rate‐limiting conductive channel at the apical membrane. In addition, the studies on the effects of variations in transmural p.d. on chloride fluxes revealed a symmetrical voltage‐independent component, dependent on the presence of chloride in the trans compartment, and it was suggested that this component may reflect the presence of a chloride‐chloride exchange mechanism.

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“…The concentration of acetazolamide required to significantly reduce sodium chloride absorption, however, was greater (1 mM) than the concentration required to inhibit the enzyme in broken cell preparations (0.1 mM) (12,31). Such high concentrations are often needed to inhibit carbonic anhydrase activity in gastrointestinal tissues mounted in Ussing flux chambers (4,18,32). This may reflect the moderate water and lipid solubility of acetazolamide and its limited diffusion into tissues (31).…”

Section: Discussionmentioning

confidence: 99%

Effects of acid-base variables on ion transport in rat colon.

Goldfarb¹,

Egnor²,

Charney³

1988

J. Clin. Invest.

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Alterations in arterial acid-base variables have important effects on colonic electrolyte transport in vivo. To confirm the relative effects of these variables and to characterize the transport processes involved, we measured unidirectional 22Na and 36C1 fluxes across short-circuited, distal colonic mucosa of Sprague-Dawley rats. Stripped tissues were studied in Hepes buffer and in Ringer's solutions at HCO3 concentrations of 11, 21, and 39 mM, and CO2 tensions between 0 and 69.6 mmHg. Increases in Pco2, but not in either pH or HCO3 concentration, caused similar increases in J.'t and J2, (net flux of sodium and chloride, respectively) from -0.2±03 and -1.5±0.4 ,geq/ cm per h at Pco2 = 0 to 6.8±0.6 and 7.6±0.7 ,ueq/cm2 per h, respectively, at Pco2 = 69.6 mmHg. These increases were accounted for by changes in Jms and were accompanied by small decreases in Isc. 1 mM acetazolamide decreased both J.A= and J~t and their responses to increases in Co2. 0.75 mM luminal amiloride prevented the increase in sodium absorption, but did not affect the C02-induced increase in chloride absorption. In the presence of amiloride, CO2 increased JR (residual flux). 0.1 mM luminal furosemide did not affect the C02-induced increases in J'w in the absence or presence of amiloride.Changes in HCO3 concentration did not alter JRA We conclude that ambient CO2 effects active, electroneutral sodium absorption in the rat distal colon. The process stimulated by CO2 is dependent on mucosal carbonic anhydrase activity and most likely represents Na/H and CI/HCO3 ion exchange.

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Effect of acetazolamide on sodium and chloride transport by in vitro rabbit ileum

Cited by 59 publications

References 0 publications

Ricinoleic acid stimulation of active anion secretion in colonic mucosa of the rat.

Ricinoleic acid stimulation of active anion secretion in colonic mucosa of the rat.

Transport of sodium and chloride across rat gastric mucosa in vitro.

Effects of acid-base variables on ion transport in rat colon.

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