Exendin-4, a new peptide from Heloderma suspectum venom, potentiates cholecystokinin-induced amylase release from rat pancreatic acini

Ravindra Malhotra, Latika Singh, John Eng, Jean Pierre Raufman

Research output: Contribution to journalArticlepeer-review

42 Scopus citations

Abstract

We examined the actions of exendin-4, a new peptide isolated from Heloderma suspectum venom, on dispersed acini from rat pancreas. Exendin-4 caused a 3-fold increase in cAMP but did not alter cellular calcium concentration. Exendin-4-induced increases in cAMP were inhibited by an exendin-receptor antagonist, exendin (9-39)NH2, but not by VIP-receptor antagonists. Whereas up to 1 μM exendin-4 alone did not alter amylase release, potentiation of enzyme release was observed when the peptide (> 30 pM) was combined with cholecystokinin. Potentiation of amylase release was also observed when exendin-4 was combined with carbamylcholine, bombesin or a calcium ionophore, A23187. These results indicate that stimulation of exendin receptors on rat pancreatic acini causes an increase in cellular cAMP. Although this increase in cAMP alone does not result in amylase release, combination of exendin-4 with agents that increase cell calcium results in potentiation of amylase release.

Original languageEnglish
Pages (from-to)149-156
Number of pages8
JournalRegulatory Peptides
Volume41
Issue number2
DOIs
StatePublished - 22 Sep 1992
Externally publishedYes

Keywords

  • Enzyme secretion
  • Potentiation
  • Vasoactive intestinal peptide
  • cAMP

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