Activity of oxyntomodulin on gastric acid secretion induced by histamine or a meal in the rat.
Conscious rats with chronic gastric fistula were trained for drinking a 14-ml milk meal. The activity of an intestinal hormone, oxyntomodulin (OXM), was studied in this model and compared to that observed when histamine was the stimulus. Under histamine (0.25 mg.kg-1.h-1) stimulation, OXM at doses (60-120 pmol.kg-1.h-1) that induced physiological circulating levels inhibited gastric acid secretion up to 50%. Under meal stimulation, OXM reduced up to 29% acid secretion at doses (1-1.5 nmol.kg-1.h-1) inducing supraphysiological levels. We conclude that at physiological concentrations OXM cannot counteract the complex processes triggered by a meal. OXM would be a component of enterogastrone, a combination of several intestinal hormones acting in synergy. The OXM action is related to pathways recognizing the C-terminal 19-37 moiety of the molecule.
Jarrousse
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C
Centre CNRS-INSERM de Pharmacologie Endocrinologie U376, Montpellier, France.
Carles-Bonnet
C
C
Niel
H
H
Bataille
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D
D000818:Animals; D004435:Eating; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000187:drug effects*; D004763:Glucagon-Like Peptides / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D006632:Histamine / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008892:Milk; D053772:Oxyntomodulin; D010446:Peptide Fragments / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D053772:Oxyntomodulin; D010446:Peptide Fragments; C081298:oxyntomodulin (19-37); D004763:Glucagon-Like Peptides; D006632:Histamine