Release and degradation of neurotensin during perfusion of rat small intestine with lipid.
The levels of neurotensin (NT) and its metabolite, the N-terminal octapeptide (NT1-8), identified by HPLC and measured by RIA, were increased in the hepatic-portal circulation of the anesthetized rat during perfusion of the small intestine with a lipid solution, while levels of both peptides remained unchanged in the general circulation. There was no significant arteriovenous difference for NT or NT1-8 during saline perfusion of the small intestine. Plasma collected from the superior mesenteric vein during the infusion of [3H]NT into the superior mesenteric artery showed major peaks of radioactivity with the retention times of NT1-8 and NT1-11 on HPLC. Only 12% of the radioactivity recovered from plasma was intact NT. These studies demonstrate that chromatographically identified NT and its metabolite, NT1-8, are elevated in the portal circulation but not systemic circulation during lipid perfusion and that the small intestine may be both the site of release and metabolism of NT.
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003840:Deoxycholic Acid / Q000031:analogs & derivatives*; D005260:Female; D005989:Glycerides / Q000494:pharmacology*; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D008823:Micelles; D009496:Neurotensin / Q000378:metabolism*; D019301:Oleic Acid; D009829:Oleic Acids / Q000494:pharmacology*; D010446:Peptide Fragments / Q000378:metabolism; D010477:Perfusion; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D011919:Rats, Inbred Strains; D013657:Taurodeoxycholic Acid / Q000494:pharmacology*; D014316:Tritium
D005989:Glycerides; D008823:Micelles; D009829:Oleic Acids; D010446:Peptide Fragments; D003840:Deoxycholic Acid; D014316:Tritium; D019301:Oleic Acid; D009496:Neurotensin; D013657:Taurodeoxycholic Acid; C041968:neurotensin (1-8); C005953:monoolein; D011761:Pyrrolidonecarboxylic Acid