Pentagastrin is a synthetic polypeptide and cholecystokinin-2 (CCK2) receptor agonist.1 It binds selectively to CCK2 receptors in guinea pig brain over CCK1 receptors in rat pancreas (IC50s = 11 and 1,100 nM, respectively). Pentagastrin increases calcium influx and polyphosphoinositide turnover in rat GH3 pituitary cells (EC50s = 23 and 3.9 nM, respectively). It also increases histidine decarboxylase activity in mucous- and endocrine cell-enriched isolated rabbit fundic mucosal cells (EC50 = 2.9 nM).2 Pentagastrin induces contraction of isolated pig ileum smooth muscle cells in vitro (EC50 = 30 pM).3 It increases gastric acid and pepsin secretion in conscious cats in vivo (ED50s = 1.29 and 57.3 nmol/kg2 per hour, respectively).4 Formulations containing pentagastrin have previously been used as a diagnostic aid to evaluate gastric acid secretory function.
1.Smith, A.J., and Freedman, S.B.CCK-B receptor-mediated stimulation of polyphosphoinositide turnover in GH3 pituitary cells in response to cholecystokinin and pentagastrinLife Sci.58(11)883-895(1996) 2.Hollande, F., Bali, J.P., and Magous, R.Neurohormonal regulation of histamine synthesis in isolated rabbit fundic mucosal cellsAm. J. Physiol.266(3 Pt. 1)G395-G405(1994) 3.Botella, A., Delvaux, M., Berry, P., et al.Cholecystokinin and gastrin induce cell contraction in pig ileum by interacting with different receptor subtypesGastroenterology102(3)779-786(1992) 4.Vagne, M., Collinet, M., Cuber, J.C., et al.Effect of porcine gastrin releasing peptide on gastric secretion and motility and the release of hormonal peptides in conscious cats.Peptides8(3)423-430(1987)