An amino-terminal fragment of LCRF, LCRF-(1-35), has the same activity as the natural peptide

Alan W. Spannagel, Joseph R. Reeve, Rodger A. Liddle, Difu Guan, Gary M. Green

Research output: Contribution to journalArticlepeer-review


A cholecystoki nin (CCK)-releasing peptide, luminal CCK-releasing factor (LCRF), has been purified from rat jejunal secretion. Amino acid analysis and mass spectral analysis showed that the purified peptide is composed of 70-75 amino acid residues and has a mass of 8, 136 Da. Microsequence analysis of LCRF yielded an amino acid sequence for the ammo-terminal 41 residues. To determine the biologically active region of the molecule, a peptide was synthesized consisting of the aminoterminal 35 amino acids of LCRF. In this study, intraduodenal infusion of LCRF-(1-35) significantly stimulated pancreatic secretion in conscious rats. The dose-response curves to LCRF-(1-35) and to monitor peptide were similar and biphasic, with higher doses producing submaximal pancreatic secretory responses. The CCK-A receptor antagonist MK-329 abolished the pancreatic secretory response to intraduodenally infused LCRF-(1-35). These results demonstrate that LCRF biological activity is contained within the amino-terminal 35-amino acid portion of LCRF, and this fragment may be useful for investigating the role of LCRF in gastrointestinal function.

Original languageEnglish (US)
Pages (from-to)G706-G712
JournalAmerican Journal of Physiology
Issue number3 PART 1
StatePublished - 1997
Externally publishedYes


  • Exocrine pancreas
  • Luminal cholecystokinin-releasing factor
  • Negative feedback regulation

ASJC Scopus subject areas

  • Physiology (medical)


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