Xenopsin- and neurotensin-like peptides in gastric juice from patients with duodenal ulcers.
Using an anti-serum directed against the COOH-terminal region of neurotensin and an anti-serum raised xenopsin in radioimmunoassays, the presence of neurotensin- and xenopsin-like immunoreactivity in Sep-pak extracts of human gastric juice was demonstrated. An anti-serum directed against the NH2-terminal to central residues of neurotensin and an anti-serum directed against a conformation, present only in the intact peptide, did not detect immunoreactivity in the juice. Infusions of pentagastrin at doses of 0.75 micrograms kg-1 h-1 and 1.5 micrograms kg-1 h-1 resulted in significant (P less than 0.05) increases in the total amount of xenopsin-like, but not neurotensin-like, immunoreactivity released in the juice compared with basal release. No significant differences in the release of xenopsin- or neurotensin-like immunoreactive were observed between patients with selective proximal vagotomy and patients without operation. Analysis by gel permeation chromatography and high performance liquid chromatography demonstrated that both the neurotensin- and xenopsin-like immunoreactivity was heterogeneous and an increase in molecular complexity on pentagastrin-stimulation was observed. As both neurotensin and xenopsin inhibit gastric exocrine activity, the presence of immunochemically related substances in gastric juice may have physiological relevance.
D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004381:Duodenal Ulcer / Q000503:physiopathology*; D005260:Female; D005750:Gastric Juice / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D010455:Peptides; D011863:Radioimmunoassay; D029867:Xenopus Proteins
D009479:Neuropeptides; D009842:Oligopeptides; D010455:Peptides; D029867:Xenopus Proteins; C031644:neurotensin-like immunoreactivity; C016832:xenopsin