[CAS NO. 2482-00-0]  Agmatine sulfate

Agmatine binds to alpha 2-adrenergic and imidazoline receptors and stimulates release of catecholamines from adrenal chromaffin cells. Its biosynthetic enzyme, arginine decarboxylase, is present in brain. Agmatine, locally synthesized, is an endogenous agonist at imidazoline receptors, a noncatecholamine ligand at alpha 2-adrenergic receptors and may act as a neurotransmitter ^[1] . Agmatine is synthesized in the brain, stored in synaptic vesicles in regionally selective neurons, accumulated by uptake, released by depolarization, and inactivated by agmatinase. Agmatine inhibits nitric oxide synthase, and induces the release of some peptide hormones ^[2] . Agmatine, 4-(aminobutyl)guanidine, is produced by decarboxylation of L-arginine by the enzyme arginine decarboxylase. Agmatine is a competitive inhibitor of all NOS isoenzymes but not an NO precursor. K _i values are approximately 660 µM (NOS I), 220 µM (NOS II) and 7.5 mM (NOS III) ^[3] . Agmatine stimulates nitrite production three-fold above basal nitrite formation by endothelial cells. Agmatine displaces [ ³ H]-idazoxan from endothelial cellmembranes and is found to induce transients in the cytosolic calcium of endothelial cells. The transients could be downregulated by repeated exposure to agmatine but are not affected by pretreatment with norepinephrine ^[4] .

MCE has not independently confirmed the accuracy of these methods. They are for reference only.