A polyamine metabolite; binds to human α2A-, α2B-, and α2c-ARs and I2b (Kis = 46.98, 164.4, 26.3, and 74.4 μM, respectively); inhibits NMDAR in a voltage- and concentration-dependent manner in primary rat hippocampal neurons and antagonizes nAChR in intact chick retina at 1 mM; competitively inhibits neuronal, macrophage, endothelial, and inducible NOS (Kis = 660, 220, 7,500, and 260 μM, respectively) and irreversibly inactivates neuronal NOS in the presence of calmodulin (Ki = 29 μM); lowers the ED50 value by 5.2- and 4.7-fold for morphine and DPDPE, respectively, in mice in a tail flick assay (10 mg/kg); increases the nephron filtration rate when microperfused into the urinary space in rats