Agmatine (Agm)

Agmatine is the decarboxylation product of the amino acid arginine and is an intermediate in polyamine biosynthesis. It is discussed as a putative neurotransmitter. It is synthesized in the brain, stored in synaptic vesicles, accumulated by uptake, released by membrane depolarization, and inactivated by agmatinase. Agmatine binds to α2-adrenergic receptor and imidazoline binding sites, and blocks NMDA receptors and other cation ligand-gated channels. Agmatine inhibits or inactivates nitric oxide synthase (NOS), and it induces the release of some peptide hormones. agmatine administered orally abolished the depressive-like behavior induced by the administration of the pro-inflammatory cytokine, tumor necrosis factor (TNF-α) in mice. Agmatine exerts antidepressant like effects via NPYergic system possibly mediated by the NPY Y1 receptor subtypes in rats.