The relationship between local anesthetic effect of QX-314 and TRPV1 expression following inferior alveolar nerve transection in rats

据报道，QX-314与辣椒素一起使用可产生持久的急性疼痛阻滞。然而，关于它们对神经损伤后神经性疼痛（NP）的治疗作用的报道很少，神经性疼痛涉及感觉神经元的各种生物物理和分子变化。本研究在下肺泡神经（IAN）横断后，在NP和非NP条件下评估了这种组合的效果。不同条件下辣椒素诱导的QX-314局麻阻滞程度不同；然而，在NP条件下，横断后2周未观察到阻滞。免疫组织化学研究显示，随着时间的推移，瞬时受体电位香草样蛋白1 （TRPV1）表达的再生神经元数量逐渐增加。表达TRPV1的无髓鞘神经元再生缓慢，特别是在NP存在时。此外，TRPV1的表达向髓鞘纤维转移，这种转移在NP条件下比在非NP条件下更强烈。

QX-314 with capsaicin has been reported to produce long-lasting block of acute pain. However, little is reported of their effectiveness on neuropathic pain (NP) after nerve injury which involves various biophysical and molecular changes in sensory neurons. In this study the effect of this combination was evaluated under NP and non-NP conditions after inferior alveolar nerve (IAN) transection.The magnitude of QX-314 with capsaicin induced local anesthetic block varied under various conditions; however, no block was observed under NP conditions at 2 weeks after transection. Immunohistochemical study revealed that the number of regenerated neurons with transient receptor potential vanilloid 1 (TRPV1) expression gradually increased over time after transection. Unmyelinated neurons expressing TRPV1 regenerated slowly, especially in the presence of NP. In addition, TRPV1 expression shifted to myelinated fibers and this shift was more intense under NP than under non-NP conditions.