钠离子通道1.8参与调控大鼠颞下颌关节炎性痛及其性别差异

Involvement of Sodium Channel Nav1.8 in Inflamed Temporomandibular Joint Pain and in Sex Differences of Inflamed Temporomandibular Joint Pain

通过观察实验性颞下颌关节炎症是否影响大鼠三叉神经节钠离子通道1.8(Nav1.8)mRNA的表达及其在雌、雄大鼠的表达有否差异,即探讨钠离子通道是否参与调控颞下颌关节炎性痛及其性别差异。通过注射完全弗氏佐剂于SD大鼠颞下颌关节上腔建立颞下颌关节炎症模型。采用组织病理学手段确认关节炎症。通过测量摆头阈值及2 h进食量评估大鼠疼痛行为的改变。采用实时荧光定量PCR方法评估三叉神经节Nav1.8 mRNA变化。结果显示,诱导颞下颌关节炎症24h后,滑膜组织出现增生、炎细胞浸润及血管增生等滑膜炎特征。摆头阈值及2 h进食量明显降低,且雌性摆头阈值及2 h进食量低于雄性。同时三叉神经节Nav1.8 mRNA出现上调,且雌性Nav1.8 mRNA上调幅度高于雄性。这些结果提示,三叉神经节Nav1.8可能参与调控颞下颌关节炎性痛以及其性别差异,为进一步理解颞下颌关节紊乱病相关疼痛及其性别差异提供实验依据。

To study whether temporomandibular joint （TMJ） inflammation could influence trigeminal ganglionic Navl. 8 mRNA expression and whether trigeminal ganglionic expression of Navl. 8 in the male or female was differentially influenced by the joint inflammation, complete Frennd＇ s adjuvant （CFA） was injected into TMJs of SD male or female rats to induce TMJ inflammation. Histopathologic examination was used to evaluate TMJ inflamma- tion. Head withdrawal threshold and food intake were used to evaluate pain behavior. Real-time PCR was used to evaluate Navl. 8 mRNA expression in the trigeminal ganglion. The features of synovitis were observed only in the CFA-injected TMJ, but not in the control TMJ. Food intake and head withdrawal threshold significantly decreased in the inflamed group compared with the control group and more decreased in the female group than in the male group. Correspondingly, the expression of trigeminal ganglionic Navl. 8 mRNA was upregulated in the inflamed group compared with the control group and more upregulated in the female group than in the male group. These re- sults suggest that Navl. 8 may be involved in inflamed TMJ pain and in sex differences of inflamed TMJ pain.