Evidence for in Vivo Scavenging by Aminoguanidine of Formaldehyde Produced via Semicarbazide-Sensitive Amine

Aminoguanidine (AG) is capable of preventing advanced pro-tein glycation and inhibiting the activity of enzymes with car-bonyl groups as cofactors, such as nitric-oxide synthase (NOS) and semicarbazide-sensitive amine oxidase (SSAO). The hy-drazide moiety of AG can also interact with different endoge-nous carbonyl metabolites and potentially harmful endogenous aldehydes. Aldehydes can be generated via different pathways, such as lipid peroxidation (malondialdehyde and 4-hy-droxynonenal), oxidative deamination (aldehydes), and carbo-hydrate metabolism (methylglyoxal). Formaldehyde and meth-ylglyoxal are produced via SSAO-catalyzed deamination of methylamine and aminoacetone, respectively. An increase in SSAO-mediated deamination is known to be associated with various vascular disorders, such as diabetic complications. The