Non-peptide neuropeptide y antagonists derived from the histamine H2 agonist arpromidine: Role of the guanidine group

Arpromidine analogs in which the guanidino group was replaced or substituted were investigated in functional studies for NPY Y1 and histamine H1 antagonism as well as for H2 agonism (HEL cells, guinea pig ileum and atrium). A basic guanidine or amidine system proved to be important for both Y1 and H2 receptor activity. Additional guanidine substitution (Me, cHex, Ph) is compatible with Y1 antagonism but not with high H2 agonist potency.