Reduced nerve injury-induced neuropathic pain in kinin B-1 receptor knock-out mice

• Autor(a) principal: Ferreira, Juliano
• Data de Publicação: 2005
• Outros Autores: Beirith, Alessandra, Mori, Marcelo A S [UNIFESP], Araujo, Ronaldo C., Bader, Michael, Pesquero, Joao Bosco [UNIFESP], Calixto, Joao B
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.1523/JNEUROSCI.2466-04.2005; http://repositorio.unifesp.br/handle/11600/28193
• topic: neuropathic pain; allodynia; hyperalgesia; B-1 receptor; kinin; bradykinin

Injury to peripheral nerves often results in a persistent neuropathic pain condition that is characterized by spontaneous pain, allodynia, and hyperalgesia. Nerve injury is accompanied by a local inflammatory reaction in which nerve-associated and immune cells release several pronociceptive mediators. Kinin B-1 receptors are rarely expressed in nontraumatized tissues, but they can be expressed after tissue injury. Because B-1 receptors mediate chronic inflammatory painful processes, we studied their participation in neuropathic pain using receptor gene-deleted mice. in the absence of neuropathy, we found no difference in the paw-withdrawal responses to thermal or mechanical stimulation between B-1 receptor knock-out mice and 129/J wild-type mice. Partial ligation of the sciatic nerve in the wild-type mouse produced a profound and long-lasting decrease in thermal and mechanical thresholds in the paw ipsilateral to nerve lesion. Threshold changed neither in the sham-operated animals nor in the paw contralateral to lesion. Ablation of the gene for the B-1 receptor resulted in a significant reduction in early stages of mechanical allodynia and thermal hyperalgesia. Furthermore, systemic treatment with the B-1 selective receptor antagonist des-Arg(9)-[Leu(8)]-bradykinin reduced the established mechanical allodynia observed 7-28d after nerve lesion in wild-type mice. Partial sciatic nerve ligation induced an upregulation in B-1 receptor mRNA in ipsilateral paw, sciatic nerve, and spinal cord of wild-type mice. Together, kinin B-1 receptor activation seems to be essential to neuropathic pain development, suggesting that an oral-selective B-1 receptor antagonist might have therapeutic potential in the management of chronic pain.