grp (human) (trifluoroacetate salt)

Gastrin-releasing peptide (GRP) is a neuropeptide that stimulates gastrin release. It binds to (Ki = 300 nM) and stimulates amylase secretion in rat pancreatic AR42J cells (EC50 = 0.3 nM). GRP increases proliferation of human liver carcinoma HepG2 and MHCC97H cells but does not affect the proliferation of normal HL-7702 liver cells at a concentration of 1 nM. In vivo, GRP (0.35 nmol/kg/h) increases both pancreatic exocrine secretion and pancreatic polypeptide (PP) release in rats. It dose-dependently stimulates gastrin, pancreatic amylase, lipase, bilirubin, and acid output and induces gallbladder contraction in humans when administered at doses ranging from 1 to 27 pmol/kg per hour.

Tyr-α-CGRP is an N-terminal extended tyrosinated analogue of α-calcitonin gene-related peptide . It binds to amylin receptors AMY1 and AMY3 in COS-7 cells expressing the human receptors (IC50s = 141 and 1.86 nM, respectively). Tyr-α-CGRP also binds to and stimulates cAMP accumulation in rat L6 myocytes (IC50 = 4 nM; EC50 = 12 nM). It also binds to rat brain and spleen membrane preparations (IC50s = 0.2 and 0.5 nM, respectively), induces positive chronotropic and inotropic effects in isolated right and left guinea pig atria (EC50s = 282 and 74 nM, respectively), and inhibits the twitch response in rat vas deferens (EC50 = 1.9 nM).