L-654284

Description

L-654284 is an ?2-adrenergic receptor antagonist with significant selectivity. L-654284 competes with the binding of 3H-clonidine and 3H-rauwolscine in vitro and shows Ki values of 0.8 nM and 1.1 nM, respectively. L-654284 can block the protrusion effect of clonidine in isolated vas deferens in rats, with a pA2 value of 9.1. L-654284 exhibits remarkable selectivity for ?2 and ?1 adrenergic receptors, and exhibits a Ki of 110 nM in inhibiting 3H-prazosin binding. L-654284 can significantly increase the turnover rate of norepinephrine in rat cerebral cortex in vivo, showing ?2-adrenergic receptor blocking activity in the central nervous system.