Tags

Type your tag names separated by a space and hit enter

The route of administration (enteral or parenteral) affects the conversion of isotopically labeled L-[2-15N]glutamine into citrulline and arginine in humans.
JPEN J Parenter Enteral Nutr 2007 Sep-Oct; 31(5):343-48; discussion 349-50JJ

Abstract

BACKGROUND

Glutamine exhibits numerous beneficial effects in experimental and clinical studies. It has been suggested that these effects may be partly mediated by the conversion of glutamine into citrulline and arginine. The intestinal metabolism of glutamine appears to be crucial in this pathway. The present study was designed to establish the effect of the feeding route, enteral or parenteral, on the conversion of exogenously administered glutamine into citrulline and arginine at an organ level in humans, with a focus on gut metabolism.

METHODS

Sixteen patients undergoing upper gastrointestinal surgery received an IV or enteral (EN) infusion of L-[2-(15)N]glutamine. Blood was sampled from a radial artery and from the portal and right renal vein. Amino acid concentrations and enrichments were measured, and net fluxes of [(15)N]-labeled substrates across the portal drained viscera (PDV) and kidneys were calculated from arteriovenous differences and plasma flow.

RESULTS

Arterial [(15)N]glutamine enrichments were significantly lower during enteral tracer infusion (tracer-to-tracee ratio [labeled vs unlabeled substrate, TTR%] IV: 6.66 +/- 0.35 vs EN: 3.04 +/- 0.45; p < .01), reflecting first-pass intestinal metabolism of glutamine during absorption. Compared with IV administration, enteral administration of the glutamine tracer resulted in a significantly higher intestinal fractional extraction of [(15)N]glutamine (IV: 0.15 +/- 0.03 vs EN: 0.44 +/- 0.08 micromol/kg/h; p < .01). Furthermore, enteral administration of the glutamine tracer resulted in higher arterial enrichments of [(15)N]citrulline (TTR% IV: 5.52 +/- 0.44 vs EN: 8.81 +/- 1.1; p = .02), and both routes of administration generated a significant enrichment of [(15)N]arginine (TTR% IV: 1.43 +/- 0.12 vs EN: 1.68 +/- 0.18). This was accompanied by intestinal release of [(15)N]citrulline across the PDV, which was higher with enteral glutamine (IV: 0.38 +/- 0.07 vs EN: 0.72 +/- 0.11 micromol/kg/h; p = .02), and subsequent [(15)N]arginine release in both groups.

CONCLUSIONS

In humans, the gut preferably takes up enterally administered glutamine compared with intravenously provided glutamine. The route of administration, enteral or IV, affects the quantitative conversion of glutamine into citrulline and subsequent renal arginine synthesis in humans.

Authors+Show Affiliations

Department of Surgery, VU University Medical Center, Amsterdam, The Netherlands.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17712141

Citation

Ligthart-Melis, Gerdien C., et al. "The Route of Administration (enteral or Parenteral) Affects the Conversion of Isotopically Labeled L-[2-15N]glutamine Into Citrulline and Arginine in Humans." JPEN. Journal of Parenteral and Enteral Nutrition, vol. 31, no. 5, 2007, pp. 343-48; discussion 349-50.
Ligthart-Melis GC, van de Poll MC, Dejong CH, et al. The route of administration (enteral or parenteral) affects the conversion of isotopically labeled L-[2-15N]glutamine into citrulline and arginine in humans. JPEN J Parenter Enteral Nutr. 2007;31(5):343-48; discussion 349-50.
Ligthart-Melis, G. C., van de Poll, M. C., Dejong, C. H., Boelens, P. G., Deutz, N. E., & van Leeuwen, P. A. (2007). The route of administration (enteral or parenteral) affects the conversion of isotopically labeled L-[2-15N]glutamine into citrulline and arginine in humans. JPEN. Journal of Parenteral and Enteral Nutrition, 31(5), pp. 343-48; discussion 349-50.
Ligthart-Melis GC, et al. The Route of Administration (enteral or Parenteral) Affects the Conversion of Isotopically Labeled L-[2-15N]glutamine Into Citrulline and Arginine in Humans. JPEN J Parenter Enteral Nutr. 2007;31(5):343-48; discussion 349-50. PubMed PMID: 17712141.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The route of administration (enteral or parenteral) affects the conversion of isotopically labeled L-[2-15N]glutamine into citrulline and arginine in humans. AU - Ligthart-Melis,Gerdien C, AU - van de Poll,Marcel C G, AU - Dejong,Cornelis H C, AU - Boelens,Petra G, AU - Deutz,Nicolaas E P, AU - van Leeuwen,Paul A M, PY - 2007/8/23/pubmed PY - 2007/12/7/medline PY - 2007/8/23/entrez SP - 343-48; discussion 349-50 JF - JPEN. Journal of parenteral and enteral nutrition JO - JPEN J Parenter Enteral Nutr VL - 31 IS - 5 N2 - BACKGROUND: Glutamine exhibits numerous beneficial effects in experimental and clinical studies. It has been suggested that these effects may be partly mediated by the conversion of glutamine into citrulline and arginine. The intestinal metabolism of glutamine appears to be crucial in this pathway. The present study was designed to establish the effect of the feeding route, enteral or parenteral, on the conversion of exogenously administered glutamine into citrulline and arginine at an organ level in humans, with a focus on gut metabolism. METHODS: Sixteen patients undergoing upper gastrointestinal surgery received an IV or enteral (EN) infusion of L-[2-(15)N]glutamine. Blood was sampled from a radial artery and from the portal and right renal vein. Amino acid concentrations and enrichments were measured, and net fluxes of [(15)N]-labeled substrates across the portal drained viscera (PDV) and kidneys were calculated from arteriovenous differences and plasma flow. RESULTS: Arterial [(15)N]glutamine enrichments were significantly lower during enteral tracer infusion (tracer-to-tracee ratio [labeled vs unlabeled substrate, TTR%] IV: 6.66 +/- 0.35 vs EN: 3.04 +/- 0.45; p < .01), reflecting first-pass intestinal metabolism of glutamine during absorption. Compared with IV administration, enteral administration of the glutamine tracer resulted in a significantly higher intestinal fractional extraction of [(15)N]glutamine (IV: 0.15 +/- 0.03 vs EN: 0.44 +/- 0.08 micromol/kg/h; p < .01). Furthermore, enteral administration of the glutamine tracer resulted in higher arterial enrichments of [(15)N]citrulline (TTR% IV: 5.52 +/- 0.44 vs EN: 8.81 +/- 1.1; p = .02), and both routes of administration generated a significant enrichment of [(15)N]arginine (TTR% IV: 1.43 +/- 0.12 vs EN: 1.68 +/- 0.18). This was accompanied by intestinal release of [(15)N]citrulline across the PDV, which was higher with enteral glutamine (IV: 0.38 +/- 0.07 vs EN: 0.72 +/- 0.11 micromol/kg/h; p = .02), and subsequent [(15)N]arginine release in both groups. CONCLUSIONS: In humans, the gut preferably takes up enterally administered glutamine compared with intravenously provided glutamine. The route of administration, enteral or IV, affects the quantitative conversion of glutamine into citrulline and subsequent renal arginine synthesis in humans. SN - 0148-6071 UR - https://www.unboundmedicine.com/medline/citation/17712141/The_route_of_administration__enteral_or_parenteral__affects_the_conversion_of_isotopically_labeled_L_[2_15N]glutamine_into_citrulline_and_arginine_in_humans_ L2 - https://doi.org/10.1177/0148607107031005343 DB - PRIME DP - Unbound Medicine ER -