Bone cancer pain is considered to be mechanistically unique compared with inflammatory or neuropathic pain states. Toll-like receptor 4 (TLR4) is a transmembrane receptor protein which has been reported to be involved in neuropathic pain. However, the role of TLR4 in bone cancer pain is still unclear. Therefore, the aim of this study is to investigate the hypothesis that oxytocin may ameliorate bone cancer pain by suppressing TLR4 in spinal cord. Behavioral analysis and molecular biological experiments were carried out. Our data demonstrated that intrathecally delivery of oxytocin significantly ameliorated the mechanical allodynia and thermal hyperalgesia in bone cancer pain rats. Moreover, oxytocin suppressed the up-regulation of TLR4 and proinflammatory cytokines TNFα and IL-1β in spinal cord of bone cancer pain rats. Therefore, we concluded that intrathecal administration of oxytocin relieves bone cancer pain by suppressing the up-regulation of TLR4, TNFα and IL-1β in spinal cord. Oxytocin possesses analgesic efficacy against bone cancer pain and deserves further to confirm its effectiveness in clinically relevant of cancer pain.

与炎性或神经性疼痛状态相比，骨癌疼痛被认为在机械上是独特的。Toll样受体4（TLR4）是一种跨膜受体蛋白，据报道与神经性疼痛有关。但是，TLR4在骨癌疼痛中的作用仍不清楚。因此，本研究的目的是研究催产素可通过抑制脊髓中的TLR4减轻骨癌疼痛的假说。进行了行为分析和分子生物学实验。我们的数据表明，鞘内注射催产素可显着改善骨癌疼痛大鼠的机械异常性疼痛和热痛觉过敏。此外，催产素抑制骨癌疼痛大鼠脊髓中TLR4和促炎细胞因子TNFα和IL-1β的上调。因此，我们得出的结论是，鞘内注射催产素可通过抑制脊髓中TLR4，TNFα和IL-1β的上调来减轻骨癌的疼痛。催产素对骨癌疼痛具有止痛作用，还应进一步证实其在临床上与癌痛相关的有效性。