Effect of Bicarbonate, Acetate, and Citrate on Water and Sodium Movement in Normal and Cholera Toxin-Treated Rat Small Intestine

Rolston, D. D. K.; Kelly, Michael J.; Borodo, M M; Dawson, A. M.; Farthing, M. J. G.

doi:10.3109/00365528909092231

Cited by 23 publications

(10 citation statements)

References 13 publications

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“…In the cecum this effect was minimal (6.7 versus 5.3 ml). The strongest effect of CT was observed in the first 15 min of the experiment, suggesting that the removal of CT from the mucosa diminished its effect on intestinal secretion and supporting previous evidence that CT does not bind firmly to intestinal epithelial cells (1)(2)(3)(4)(5)8).…”

supporting

confidence: 83%

Effect of Cholera Toxin on Intestinal Elimination of Ciprofloxacin in Rabbits

Musafija

Barzilai

Ramon

et al. 1998

Antimicrob Agents Chemother

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The transepithelial intestinal elimination of ciprofloxacin (CPX) was studied in cholera toxin (CT)-challenged and control intestinal loops in the rabbit. CPX concentrations were similar in CT-challenged and control jejunal and ileal loops, while cecal elimination was negligible. The quantities of eliminated CPX per square centimeter of bowel wall were significantly higher in the small intestine CT-challenged loops. The mechanism of elimination of CPX in the small intestine is therefore mainly passive diffusion.

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supporting

confidence: 83%

Effect of Cholera Toxin on Intestinal Elimination of Ciprofloxacin in Rabbits

Musafija

Barzilai

Ramon

et al. 1998

Antimicrob Agents Chemother

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“…This is of interest as we have previously shown that acetate stimulates sodium absorption in the normal small intestine but not in the secreting small intestine after exposure to cholera toxin. 12 In this paper we report our studies of acetate absorption in rat jejunum using in vivo steadystate perfusion. The concentration dependence of total acetate absorption, its relationship to luminal pH and total CO2 and its inhibition by propionate and a structurally unrelated buffer were studied in the jejunum.…”

mentioning

confidence: 99%

Acetate absorption in the normal and secreting rat jejunum.

Watson

Elliott

Rolston

et al. 1990

Gut

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Acetate absorption was studied in rat jejunum using steady state perfusion in vivo. Absorption conformed to apparent saturation kinetics and was similar in magnitude to glucose absorption. When compared with normal saline, acetate perfusion was associated with luminal alkalinisation. There was no difference in total CO2 secretion when similar rates of acetate and glucose absorption were compared, suggesting that total CO2 secretion was the result of mucosal metabolism. Absorption of acetate and propionate were mutually inhibitory. Acetate absorption was also inhibited by Tris-Hepes pH 7-0. When the gut was pretreated with cholera toxin to induce a secretory state, acetate absorption was reduced by 41-9%. This effect could be reproduced if similar water secretion was osmotically induced by the addition of mannitol. These data suggest that acetate is absorbed, at least, partially by non-ionic diffusion in the rat jejunum and that its absorption is reduced in the secreting intestine by solvent drag. The mechanism by which acetate is transported across mammalian epithelia remains controversial. Previous studies in a number of species have suggested that acetate is absorbed by non-ionic diffusion.'"8 In the guinea pig proximal colon, however, it has been shown that ionized acetate is absorbed through a paracellular pathway.8 Evidence for an acetate/bicarbonate exchange mechanism has been found in human ileal brush border membrane vesicles.9 In the guinea pig gall bladder, butyrate has been shown to be absorbed passively into the epithelial cell and then back into the lumen by a chloride/butyrate exchange.'0 Finally, in the proximal renal tubule of the rabbit, short chain fatty acids are absorbed through a sodium coupled short chain fatty acid cotransport mechanism." As previous studies in the rat have used in vitro methods it is unclear which mechanism predominates in vivo. It is also unknown whether acetate absorption is preserved in the secreting intestine. This is of interest as we have previously shown that acetate stimulates sodium absorption in the normal small intestine but not in the secreting small intestine after exposure to cholera toxin. 12 In this paper we report our studies of acetate absorption in rat jejunum using in vivo steadystate perfusion. The concentration dependence of total acetate absorption, its relationship to luminal pH and total CO2 and its inhibition by propionate and a structurally unrelated buffer were studied in the jejunum. The effect on acetate absorption of comparable intestinal secretion induced by cholera toxin and by osmotic forces was also studied, to establish the effect of solvent drag. Methods STEADY STATE PERFUSION OF RAT JEJUNUM IN VIVOMale Wistar rats (180-260 g) were fasted for 18 h but allowed free access to water. Anaesthesia was induced and maintained with sodium pentobarbitone (60 mg/kg ip followed by 30 mg/kg im as required). Body temperature was maintained by a heating pad and an overhead lamp. The abdomen was opened with a midline incision and a 15-20 cm s...

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“…Another factor that can affect absorption of bioactive molecules is viscosity induced by food additives, such as guar gum [33]. Citrate, an approved food additive, is also known to increase viscosity in the presence of collagen and fibrous material [34] as well as change the water absorption profile in different parts of the small intestine [35]. It has been added to different oral rehydration formulations to modulate acidosis and glycemic index as a viscosity-promoting agent [36–38].…”

Section: Discussionmentioning

confidence: 99%

The Steady-State Serum Concentration of Genistein Aglycone Is Affected by Formulation: A Bioequivalence Study of Bone Products

Bitto

Burnett

Polito

et al. 2013

BioMed Research International

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An FDA-regulated, prescription medical food (Fosteum; 27 mg natural genistein, 200 IU cholecalciferol, 20 mg citrated zinc bisglycinate (4 mg elemental zinc) per capsule) and an over-the-counter (OTC) supplement (Citracal Plus Bone Density Builder; 27 mg synthetic genistein, 600 mg elemental calcium (calcium citrate), 400 IU vitamin D3, 50 mg magnesium, 7.5 mg zinc, 1 mg copper, 75 μg molybdenum, 250 μg boron per two tablets) were compared to a clinically proven bone formulation (27 mg natural genistein, 400 IU cholecalciferol, 500 mg elemental calcium (calcium carbonate) per tablet; the Squadrito formulation) in an 8-day steady-state pharmacokinetic (PK) study of healthy postmenopausal women (n = 30) randomized to receive 54 mg of genistein per day. Trough serum samples were obtained before the final dose on the morning of the ninth day followed by sampling at 1, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72, and 96 hrs. Total serum genistein, after β-glucuronidase/sulfatase digestion, was measured by time-resolved fluorometric assay. Maximal time (T max), concentration (C max), half-life (T 1/2), and area under the curve (AUC) were determined for genistein in each formulation. Fosteum and the Squadrito study formulation were equivalent for genistein T max (2 hrs), C max (0.7 μM), T 1/2 (18 ± 6.9 versus 21 ± 4.9 hrs), and AUC (9221 ± 413 versus 9818 ± 1370 ng·hr/mL). The OTC supplement's synthetically derived genistein, however, showed altered T max (6 hrs), C max (0.57 μM), T 1/2 (8.3 ± 1.9 hrs), and AUC (6474 ± 287 ng·hr/mL). Differences in uptake may be due to multiple ingredients in the OTC supplement which interfere with genistein absorption.

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Effect of Bicarbonate, Acetate, and Citrate on Water and Sodium Movement in Normal and Cholera Toxin-Treated Rat Small Intestine

Cited by 23 publications

References 13 publications

Effect of Cholera Toxin on Intestinal Elimination of Ciprofloxacin in Rabbits

Effect of Cholera Toxin on Intestinal Elimination of Ciprofloxacin in Rabbits

Acetate absorption in the normal and secreting rat jejunum.

The Steady-State Serum Concentration of Genistein Aglycone Is Affected by Formulation: A Bioequivalence Study of Bone Products

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