PANCREATIC POLYPEPTIDE, HUMAN

Pancreatic polypeptide is an agonist of neuropeptide Y (NPY) receptors that reduces forskolin-induced cAMP accumulation in L-M(TK-) cells recombinantly expressing human and rat Y₄ receptors (EC₅₀s = 87.1 and 36.3 pM, respectively). It binds to Y₁ and Y₅ receptors with K_i values of 19 and 3.9 nM, respectively, for human and 50 and 2.4 nM, respectively, for rhesus monkey receptors. Pancreatic polypeptide also binds to rabbit Y₁, Y₂, Y₄, and Y₅ receptors (K_is = 0.39, 0.087, 0.79, and 0.24 nM, respectively). It induces contractile responses in isolated rat colon with EC₅₀ values of 1.6 and 0.7 nM for ascending and descending colon segments, respectively. In vivo, pancreatic polypeptide (0.7-7 nmol, i.c.v.) increases food intake in rats.