title: Oral administration of a glutamine-enriched diet before or after endotoxin challenge in aged rats has limited effects.
abstract: Numerous studies indicate beneficial effects of glutamine (Gln) in many models of catabolic adult rats. No data were available for aged rats. The effects of oral L-Gln-enriched diet were tested in endotoxemic 24-mo old rats. First, rats received for 7 d (from d0 to d7) an oral diet supplemented with either L-Gln [1g/(kg. d)] or casein (Cas: isonitrogenous supply) prior to lipopolysaccharide (LPS) challenge. The rats were then killed after 24 h food deprivation (from d7 to d8). Endotoxemia induced a catabolic response as shown by muscle glutamine depletion, hyperphenylalaninemia, small bowel atrophy and impaired functionality and bacterial translocation. The Gln-enriched diet did not prevent muscle Gln depletion but significantly (P </= 0.05) enhanced plantaris protein content by 18% compared to the Cas-LPS rats and reduced the plasma phenylalanine-to-tyrosine ratio (1.32 +/- 0.05 vs. 1.54 +/- 0.10, respectively, P </= 0.01). Gut translocation and histomorphology were unaffected by diet. However, Gln pretreatment reduced the fall in sucrase and glucoamylase activities in the ileum, respectively, by 55 and 63% vs. Cas supplementation (P </= 0.05). In a second study, after endotoxin challenge, healthy 24-mo-old rats were then food-deprived for 2 d (from d0 to d2), received a nonpurified diet for 4 d (from d2 to d6), and then Cas or L-Gln-supplemented diet for 7 d (from d6 to d13). No beneficial effects of Gln supplementation were observed except an increase of 50 and 56% in sucrase and glucoamylase activities in the ileum of Gln-treated rats, (P </= 0.01 vs. healthy rats). In conclusion, the effects of L-Gln supplementation in aged endotoxemic rats were limited.
authors.affiliation: Laboratoire de Biochimie, Biologie Moléculaire et Nutrition EA 2416, Faculté de Pharmacie et Centre de Recherche en Nutrition Humaine, 28 place Henri Dunant, BP 38, 63001 Clermont-Ferrand, France.
authors.forename: M C
authors.initials: MC
authors.lastname: Farges
authors.forename: M P
authors.initials: MP
authors.lastname: Bérard
authors.forename: F
authors.initials: F
authors.lastname: Raul
authors.forename: J P
authors.initials: JP
authors.lastname: Cézard
authors.forename: B
authors.initials: B
authors.lastname: Joly
authors.forename: P
authors.initials: P
authors.lastname: Davot
authors.forename: M P
authors.initials: MP
authors.lastname: Vasson
authors.forename: L
authors.initials: L
authors.lastname: Cynober
mesh_terms: D000375:Aging / Q000378:metabolism*; D000596:Amino Acids / Q000097:blood; D000818:Animals; D018988:Bacterial Translocation / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D019446:Endotoxemia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D005973:Glutamine / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000378:metabolism; D008070:Lipopolysaccharides; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000596:Amino Acids; D008070:Lipopolysaccharides; D005973:Glutamine