Evidence for Active Transport of the Dipeptide Glycylsarcosine by Hamster Jejunum <i>in Vitro</i>

Addison, Jill M.; Burston, D.; Matthews, D. M.

doi:10.1042/cs0430907

Cited by 92 publications

(32 citation statements)

References 2 publications

(3 reference statements)

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“…The experiment entailing ingestion of histidine plus ,-alanine eliminates the possibility that the urinary carnosine had arisen from resynthesis after hydrolysis of the ingested peptide. In the experiment performed on glycyl-sarcosine, a hydrolysis-resistant dipeptide (Addison, Burston & Matthews, 1972), 10-5 % of the intact peptide was recovered in urine. In view of the remarkably short half-life of carnosine in plasma (Fig.…”

Section: Discussionmentioning

confidence: 99%

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Gardner

Illingworth

Kelleher

et al. 1991

The Journal of Physiology

139

107

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SUMMARY Healthy humans ingested the dipeptide carnosine (L-/I-alanyl-L-histidine).Their plasma levels and urinary outputs of carnosine and ,8-alanine were monitored over the following 5 h.2. Large amounts of intact carnosine (up to 14 % of the ingested dose) were recovered in the urine over the 5 h after ingestion. However, carnosine was undetectable in the plasma unless precautions were taken to inhibit blood carnosinase activity ex vivo during and after blood collection.3. The amount of carnosine recovered in urine varied substantially between subjects. It correlated negatively with carnosinase enzymic activity in the plasma. Highest carnosinase activities were observed in those subjects who regularly underwent physical training.4. Urinary recovery of the disaccharide lactulose also varied considerably between subjects, but was substantially lower than that of carnosine. There was no significant correlation between the recoveries of carnosine and lactulose. 5. When lactulose was ingested with a hypertonic solution, the urinary recovery of lactulose was generally increased. When carnosine was ingested with a hypertonic solution, the urinary recovery of carnosine was reduced: hence the paracellular route probably is not dominant for absorption of intact carnosine.6. Intact carnosine must have crossed the intestine to an extent much greater than hitherto recognized. Rapid post-absorptive hydrolysis is a severe obstacle to quantification of intact peptide absorption.

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Section: Discussionmentioning

confidence: 99%

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Gardner

Illingworth

Kelleher

et al. 1991

The Journal of Physiology

139

107

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“…Dipeptides do not compete with amino acids for mucosal uptake (23) and they have been found to increase Na absorption in man (3). Because transport of a poorly hydrolyzed dipeptide, glycylsarcosine, into hamster intestinal rings was reduced by metabolic inhibitors and by replacement of mucosal Na with potassium (14), dipeptides were thought to be cotransported with Na (23). However, evidence is accumulating that "uphill" Na-driven transport of dipeptides may not occur in the brush border of small intestine (26)(27)(28).…”

Section: Discussionmentioning

confidence: 99%

Alanine Enhances Jejunal Sodium Absorption in the Presence of Glucose Studies in Piglet Viral Diarrhea

1986

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ABSTRACT. We measured the response of jejunal sodium (Na) absorption to neutral amino acid (L-alanine) and to dipeptides (L-alanyl-L-alanine, glycylsarcosine) in normal piglets and in piglets with acute viral diarrhea after experimental infection with transmissible gastroenteritis (TGE) virus. In the TGE jejunum villi were blunted, crypts were deepened, and the epithelium was composed of relatively undifferentiated cells with reduced disaccharidase, decreased sodium-potassium-stimulated ATPase, and elevated thymidine kinase activities. The response of Na absorption to a maximal concentration of L-alanine (20 mM) or D-glucose (30 mM) was significantly blunted in TGE jejunum in Ussing chambers. However, the addition of L-alanine together with D-glucose caused a significantly greater increment of Na absorption than either L-alanine or D-glucose alone in control and TGE tissue. The effect of Na absorption of the dipeptide L-alanyl-L-alanine (10 mM), which was rapidly hydrolyzed by control and TGE mucosa, was similar to that of L-alanine (20 mM), while glycylsarcosine, a poorly hydrolyzed dipeptide, did not change net Na absorption in the jejunum. Our data support the concept of separate carrier systems for neutral amino acid and hexose in the crypt-type intestinal epithelium characterizing viral enteritis. We speculate that a sodiumcotransporting amino acid, if added to oral glucose-electrolyte solutions, could benefit oral rehydration therapy in acute viral diarrhea; neither of the dipeptides tested here can be expected to enhance absorption to any greater extent than its constituent amino acids. (Pediatr Res 20: 879-883,1986) Abbreviations Isc, short-circuit current Na, sodium JE:, Na flux from mucosa to serosa Jr;, Na flux from serosa to mucosa JPJ, net Na flux AJZ, increment in net Na flux Na+-K+-ATPase, sodium-potassium-stimulated adenosinetriphosphatase ORT, oral rehydration therapy TGE, transmissible gastroenteritis WHO, World Health Organization Received January 23, 1986; accepted April 30, 1986. Supported by a grant from the Medical Research Council of Canada. J.M.R. was a recipient of a research fellowship from the Canadian Cystic Fibrosis Foundation.All correspondence and requests for reprints should be addressed to J. Richard Hamilton, M.D., Division of Gastroenterology, The Hospital for Sick Children, 555 University Avenue. Toronto, Ontario, Canada M5G 1x8.ORT has greatly improved the outlook for millions of babies aMicted each year with acute enteritis. The current WHO/ UNICEF formulation for oral rehydration has been very effective in restoring the water and electrolyte status of patients with diarrhea, but it does not diminish stool losses (l,2). To accelerate clinical recovery and promote general acceptance of ORT, a solution that actually reduces diarrheal volume would be very desirable.One theoretical approach to improving standard ORT is to incorporate additional nonionic solute in its formulation to promote water and salt absorption in the diseased intestine. To evaluate the pathophysiologica...

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“…14 C-labelled glycylsarcosine (Gly-Sar) was used as substrate. This dipeptide is resistant to hydrolysis by peptidases of the BBM and therefore is an appropriate substrate for studying peptide uptake into intestinal epithelium (Addison et al 1972). …”

Section: Introductionmentioning

confidence: 99%

Inhibition of mucosal glycylsarcosine uptake by acetate in rat distal small intestine

1999

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Evidence for Active Transport of the Dipeptide Glycylsarcosine by Hamster Jejunum in Vitro

Cited by 92 publications

References 2 publications

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Intestinal absorption of the intact peptide carnosine in man, and comparison with intestinal permeability to lactulose.

Alanine Enhances Jejunal Sodium Absorption in the Presence of Glucose Studies in Piglet Viral Diarrhea

Inhibition of mucosal glycylsarcosine uptake by acetate in rat distal small intestine

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