AM1241

AM-1241 is a potent and selective agonist for the cannabinoid receptor CB2, with a Ki of 3.4nM at CB2 and 80x selectivity over the related CB1 receptor. AM1241 exhibits high affinity and selectivity for CB2 receptors. It also exhibits high potency in vivo. AM1241 dose-dependently reversed tactile and thermal hypersensitivity produced by ligation of the L5 and L6 spinal nerves in rats. AM1241 also inhibited flinching and thermal hyperalgesia produced by hind paw capsaicin injection. AM1241 was also active in blocking spinal nerve ligation-induced tactile and thermal hypersensitivity in mice lacking CB1 receptors (CB1-/- mice), confirming that AM1241 reverses sensory hypersensitivity independent of actions at CB1 receptors. Treatment with AM-1241 reduced both spontaneous and evoked pain, as well as reducing the bone loss and subsequent fractures due to the tumor.