Biological significance of agmatine, an endogenous ligand at imidazoline binding sites

摘要

Many publications have shown that imidazoline derivatives such as clonidine, moxonidine or rilmenidine reduce sympa- thetic tone via a central mechanism and that as a result they reduce plasma catecholamines and blood pressure(Reid et al., 1995). This reduction in blood pressure appears not to be regulated via peripheral, presynptically localized receptors, since neither catecholamine depletion by reserpine, or destruction of the nerve endings with 6-hydroxydopamine produces a notable weakening of the clonidine-induced blood pressure reduction(Haeusler, 1974a, b; Kobinger & Pichler, 1976; Finch et al., 1975).