PACAP-related peptide (PRP) is an endogenous 29-amino acid peptide that belongs to the secretin/glucagon superfamily of peptides, which includes secretin , glucagon , glucagon-like peptide-1 , GLP-2 , and pituitary adenylate cyclase-activating polypeptide . It is expressed in normal human pancreas and adrenal gland tissue and in some tumors that produce vasoactiveintestinalpeptide (VIP). PRP (1-29) is secreted by CHO-K1 cells that express human recombinant preproPACAP.
PACAP (1-38), a novel neuropeptide isolated from the bovine hypothalamus is more active than vasoactiveintestinalpeptide (VIP) in stimulating adenylate cyclase (EC50=7 nM). PACAP 1-38 (10-9 M) increased substance P (SP), gastrin releasing peptide (GRP),
VIP(6-28)(human, rat, porcine, bovine) is a potent antagonist that effectively counteracts the effects of exogenous vasoactiveintestinalpeptide (VIP) on cyclic adenosine monophosphate (cAMP) signaling.