Effects of an enteral glucose supply on protein synthesis, proteolytic pathways, and proteome in human duodenal mucosa.
Am J Clin Nutr
; 94(3): 784-94, 2011 Sep.
Article
em En
| MEDLINE
| ID: mdl-21795435
ABSTRACT
BACKGROUND:
Previous studies have shown that the glucose supply reduces postoperative insulin resistance and improves patient outcomes. However, the effects of luminal glucose on intestinal mucosal proteins remain unknown.OBJECTIVE:
We aimed to assess the effects of an enteral glucose supply on protein synthesis, proteolytic pathways, and proteome in human duodenal mucosa.DESIGN:
Twenty healthy volunteers received a 5-h enteral infusion of either saline or glucose (0.12 g · kg(-1) · h(-1)). Simultaneously, a continuous intravenous infusion of l-[1-(13)C]leucine (12 µmol · kg(-1) · h(-1)) was maintained until endoscopy. The duodenal mucosal protein fractional synthesis rate (FSR) was calculated from leucine enrichments assessed in protein and free amino acid pools by gas chromatography-mass spectrometry. Cathepsin D, calpains, and chymotrypsin-like proteasome mucosal activities were evaluated by using specific fluorogenic substrates. A 2-dimensional PAGE-based comparative proteomics analysis was also performed on additional duodenal mucosal biopsy samples to identify differentially expressed proteins.RESULTS:
Duodenal mucosal protein FSR and protease activities were not affected by glucose infusion relative to saline. Nevertheless, the comparative proteomics analysis indicated that 10 protein spots were significantly differentially expressed (ie, at least ±1.5-fold modulated; Student's t test, P < 0.05) in response to the glucose infusion relative to saline. Of the 8 proteins identified by mass spectrometry, α-enolase, cytoplasmic aconitate hydratase, and glutathione S-transferase ω-1 were upregulated, whereas epoxide hydrolase 2 was downregulated.CONCLUSION:
Enteral glucose supply affected neither duodenal mucosal protein FSR nor activities of mucosal proteases but altered the duodenal mucosal proteome by modulating the expression of several enzymes involved mainly in carbohydrate and xenobiotic metabolism. This trial is registered at clinicaltrials.gov as NCT00213551.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Peptídeo Hidrolases
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Biossíntese de Proteínas
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Carboidratos da Dieta
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Duodeno
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Glucose
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Mucosa Intestinal
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Am J Clin Nutr
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
França