Agmatine ((4-aminobutyl)guanidine,NH2-CH2-CH2-CH2-CH2-NH-C(-NH2)(=NH))is the decarboxylation product of the amino acid arginine and is anintermediate in polyamine biosynthesis. It is discussed as aputative neurotransmitter. It is synthesized in the brain, storedin synaptic vesicles, accumulated by uptake, released by membranedepolarization, and inactivated by agmatinase. Agmatine binds toα2-adrenergic receptor and imidazoline binding sites,and blocks NMDA receptors and other cation ligand-gated channels.Agmatine inhibits nitric oxide synthase (NOS), and it induces therelease of some peptide hormones.

Agmatine