| 著者 |
Vincenzi F, Targa M, Corciulo C, Tabrizi MA, Merighi S, Gessi S, Saponaro G, Baraldi PG, Borea PA, Varani K.
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| Abstract |
Cannabinoid CB(2) receptor activation by selective agonists has been shown to produce analgesic effects in preclinical models of inflammatory, neuropathic, and bone cancer pain. In this study the effect of a novel CB(2)agonist (MT178) was evaluated in different animal models of pain. First of all, in vitro competition binding experiments performed on rat, mouse, or human CB receptors revealed a high affinity, selectivity, and potency of MT178. The analgesic properties of the novel CB(2) agonist were evaluated in various in vivo experiments, such as writhing and formalin assays, showing a good efficacy comparable with that produced by the nonselective CB agonist WIN 55,212-2. A dose-dependent antiallodynic effect of the novel CB(2) compound in the streptozotocin-induced diabetic neuropathy was found. In a bone cancer pain model and in the acid-induced muscle pain model, MT178 was able to significantly reduce mechanical hyperalgesia in a dose-related manner. Notably, MT178 failed to provoke locomotor disturbance and catalepsy, which were observed following the administration of WIN 55,212-2. CB(2) receptor mechanism of action was investigated in dorsal root ganglia where MT178 mediated a reduction of [(3)H]-d-aspartate release. MT178 was also able to inhibit capsaicin-induced substance P release and NF-κB activation. These results demonstrate that systemic administration of MT178 produced a robust analgesia in different pain models via CB(2) receptors, providing an interesting approach to analgesic therapy in inflammatory and chronic pain without CB(1)-mediated central side effects.
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