The gastric factors controlling abundance of mRNA encoding the important neuropeptide, gastrin releasing peptide (GRP) in rat stomach, were examined by Northern and slot blot analysis. Withdrawal of food increased antral GRP mRNA, as did treatment of fed rats with the acid inhibitory drug, omeprazole. There was no change in GRP mRNA abundance in gastric corpus. The data indicate functionally distinct populations of GRP neurons in different regions of the stomach, and control of antral neuropeptide biosynthesis by the gastric luminal contents.
