Characteristics of putrescine uptake in isolated rat enterocytes

Kumagai, Jun; Johnson, L. R.

doi:10.1152/ajpgi.1988.254.1.g81

Cited by 32 publications

(38 citation statements)

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“…Experimental evidence indicates that the uptake of endoluminal polyamines by brush-border membrane vesicles is a selective and saturable absorptive process dependent to a large extent on their endoluminal concentration (19)(20)(21)(22). In agreement with our data, Dufour et al…”

Section: Discussionsupporting

confidence: 92%

Saccharomyces boulardii Enhances Rat Intestinal Enzyme Expression by Endoluminal Release of Polyamines

1994

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Saccharomyces boulardii is a yeast widely used in humans for the prevention and treatment of infectious enteritis and Clostridium difficile-associated enterocolopathies. After oral administration to human volunteers or growing rats, S. boulardii enhances markedly the expression of intestinal enzymes as well as the production of the polymeric immunoglobulin receptor by mechanisms that remain unknown. We have analyzed the role of the yeast polyamines as potential mediators in the intestinal trophic response. In weanling rats (d 20 to d 30), a daily dose of 100 mg of lyophilized S. boulardii produced significant (p < 0.025) increases in sucrase (157%) and maltase (47%) activities. This dose corresponded to a total oral load of 678 nmol of polyamines per day (spermidine: 376 + 32, spermine: 293 + 26, putrescine: 9.5 + 1.4 nmo11100 mg). Spermine, given orally to growing rats at doses nearly equivaSaccharomyces boulardii is a thermophilic, nontoxic yeast used in many countries for the treatment of acute infectious enteritis (I), antibiotic-induced gastrointestinal disorders (2, 3), and Clostridium dificile-associatedenterocolopathies (4, 5). The physiologic impact of the yeast on the gastrointestinal tract of mammals remains largely unknown. In a previous study (6), we have shown that the oral treatment of human volunteers and weaned rats with a lyophilized preparation of S. boulardii resulted in marked increases in the specific and total activities of brush-border membrane enzymes without morphologic alteration of the intestinal mucosa.Subsequently, w e found increased secretion of IgA and of the polymeric immunoglobulin receptor in intestinal fluid and mucosa of rats treated with S. boulardii (7). Although these changes may contribute to the explana- lent (500 nmol) to the load of polyamines provided by the yeast (678 nmol), reproduced similar enzymatic changes, including a 2.5-fold induction of sucrase, and enhanced maltase activity (+24%). Spermidine and spermine concentrations measured in the jejunal mucosa of treated rats were increased over matched controls by 21.4% (p < 0.005) and 21.9%, respectively (p < 0.002). After being centrifuged and filtered to discard residual yeast cells, 2-mL samples of jejunal and ileal fluid collected from S. boulardii-treated rats by intestinal flushing contained higher levels of spermidine (48 and 60%) and spermine (150 and 316%) than did control rats. Our data indicate that lyophilized S. boulardii exerts trophic effects on the small intestine that are likely mediated by the endoluminal release of spermine and spermidine. (Pediufr Res 36: 522-527, 1994) tion of the beneficial effects of the yeast therapy in certain intestinal disorders, the exact mechanism by which S. boulardii exerts trophic effects on the small intestinal mucosa is not elucidated. Preliminary findings (6, 7) indicate that the enhanced expression of surface membrane glycoproteins including disaccharidases and secretory component seems unrelated to an increase in cell turnover (7) or to changes in the incorp...

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Section: Discussionsupporting

confidence: 92%

Saccharomyces boulardii Enhances Rat Intestinal Enzyme Expression by Endoluminal Release of Polyamines

1994

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“…We need to learn if there is a common trans porter for all the polyamines or if there are separate uptake mechanisms for putrescine, spermidine and spermine and we must es tablish if individual polyamines stimulate, or inhibit, the transport of other polyamines. We also need to find out, by combining intestinal perfusion with bile fistulation, whether or not there is an enterohepatic cir culation of the polyamines [37], At the same time, studies of uptake of radio-labelled polyamines from the surrounding medium by enterocytes grown in culture should pro vide transport kinetic data by individual cells [38].…”

Section: Exogenous Vs Endogenous Polyaminesmentioning

confidence: 99%

“…As noted above, the fact that DFMO inhi bition of cell growth in culture systems [29][30][31][32] may be reversed by putrescine replace ment [30] strongly suggests that exogenous polyamines can indeed be transported by intestinal epithelial cells [38]. We already know, however, that the infusion of putres cine into the lumen of the rat intestine stim ulates mucosal growth [39].…”

Section: Exogenous Vs Endogenous Polyaminesmentioning

confidence: 99%

Polyamines in Intestinal Adaptation and Disease

Dowling¹

1990

Digestion

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“…In resected rats, both apical and basolateral polyamine infusions led to a stimulation of the adaptive mucosal growth [8]. Polyamine uptake in isolated enterocytes showed evidence of a Na + -independent and active transport process [9,10]. However, this model could not differentiate between the apical and basolateral components of polyamine uptake into enterocytes.…”

Section: Introductionmentioning

confidence: 99%

Polyamine Uptake Across the Basolateral Membrane of the Enterocyte Is Mediated by a High-Affinity Carrier

Milovic

Caspary

Stein³

1998

Digestion

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Background/Aims: Polyamine uptake from the circulation plays an important role in the maintenance of the intracellular polyamine content during extensive proliferation in intestinal mucosal cells. Methods: Isolated basolateral membrane vesicles of the rabbit enterocyte were used to characterize polyamine transport across the basolateral side of the intestinal epithelium. Incorporation of spermidine and spermine into the basolateral membrane was rapid, although 30–60% of polyamines were initially bound to the basolateral membrane. In order to avoid the influence of binding on the actual uptake into the vesicles, polyamine incorporation was measured at 37 and 4°C, and kinetic parameters were calculated from the difference in polyamine incorporation rates at these temperatures. Results: Uptake kinetics was saturable, with K_m values of 13.34 and 12.35 µmol/l and V_max of 159 and 105 pmol/mg protein/min for spermidine and spermine, respectively. It was also temperature dependent, with Q₁₀ values (calculated between uptake velocities at 37 and 25°C) of 2.56 for spermidine and 1.90 for spermine. At physiological pH, polyamine uptake was at its highest. Since at this pH polyamines are fully charged, charge might be essential for polyamines to be taken up across the basolateral membrane. Polyamine uptake was inhibited by di-, tri- and tetracations, and there was no evidence for sodium cotransport. Transport of putrescine was not inhibited by spermine and spermidine, although spermidine inhibited spermine uptake in a competitive manner, with K_i of 127 µmol/l. Conclusion: These results imply that a saturable high-affinity transport system for polyamine does exist at the basolateral side of the enterocyte. Such a transport system may be responsible for the active transport of polyamine into rapidly proliferating enterocytes.

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Characteristics of putrescine uptake in isolated rat enterocytes

Cited by 32 publications

References 0 publications

Saccharomyces boulardii Enhances Rat Intestinal Enzyme Expression by Endoluminal Release of Polyamines

Saccharomyces boulardii Enhances Rat Intestinal Enzyme Expression by Endoluminal Release of Polyamines

Polyamines in Intestinal Adaptation and Disease

Polyamine Uptake Across the Basolateral Membrane of the Enterocyte Is Mediated by a High-Affinity Carrier

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