Luminal glucagon-like peptide-1(7-36) amide-releasing factors in the isolated vascularly perfused rat colon.
Glucagon-like peptide-1 (GLP-1) is released from endocrine cells of the distal part of the gut after ingestion of a meal. GLP-1 secretion is, in part, under the control of hormonal and/or neural mechanisms. However, stimulation of the colonic L cells may also occur directly by the luminal contents. This was examined in the present study, using an isolated vascularly perfused rat colon. GLP-1 immunoreactivity was measured in the portal effluent after luminal infusion of a variety of compounds which are found in colonic contents (nutrients, fibers, bile acids, short-chain fatty acids (SCFAs)). Oleic acid (100 mM) or a mixture of amino acids (total concentration 250 mM), or starch (0.5%, w/v) did not increase GLP-1 secretion over basal value. A pharmacological concentration of glucose (250 mM) elicited a marked release of GLP-1 which was maximal at the end of infusion (400% of basal), while 5 mM glucose was without effect on secretion. Pectin evoked a dose-dependent release of GLP-1 over the range 0.1-0.5% (w/v) with a maximal response at 360% of basal when 0.5% pectin was infused. Cellulose or gum arabic (0.5%) did not modify GLP-1 secretion. The SCFAs acetate, propionate or butyrate (5, 20 and 100 mM) did not induce a significant release of GLP-1. Among the four bile acids tested, namely taurocholate, cholate, deoxycholate and hyodeoxycholate, the last one was the most potent at eliciting a GLP-1 response with a maximal release at 300% and 400% of the basal value when 2 and 20 mM bile acid were administered respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Plaisancié
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INSERM Unité 45, Pavillon H bis, Hôpital Edouard Herriot, Lyon, France.
Dumoulin
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Chayvialle
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JA
Cuber
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JC
D000818:Animals; D001647:Bile Acids and Salts / Q000494:pharmacology; D003106:Colon / Q000187:drug effects / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005232:Fatty Acids, Volatile / Q000494:pharmacology; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D005947:Glucose / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D010368:Pectins / Q000494:pharmacology*; D010446:Peptide Fragments / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D001647:Bile Acids and Salts; D005232:Fatty Acids, Volatile; D010446:Peptide Fragments; D003840:Deoxycholic Acid; C061970:glucagon-like peptide 1 (7-36); D004763:Glucagon-Like Peptides; C010471:hyodeoxycholic acid; D052216:Glucagon-Like Peptide 1; D010368:Pectins; D005934:Glucagon; D005947:Glucose