目的 观察康泰胶囊对IBS内脏高敏感性大鼠结肠背根神经节（dorsal root ganglion，DRG）神经元Nav1.8通道受体的影响，探讨康泰胶囊治 疗IBS的作用机制。方法 采用慢性不可预计应激法建立内脏高敏感性IBS 大鼠模型，应用腹部回缩反射（AWR）、尿D-木糖排泄实验、焦虑行为测试及血清皮质醇水平对模型 内脏敏感程度进行评估，采用实时荧光定量PCR方法检测大鼠DRG神经元上Nav1.8通道受体mRNA表达水平，观察康泰胶囊对内脏高敏感IBS大鼠DRG神经元上Nav1.8通道受体 mRNA表达水平的影响。结果 康泰胶囊可以明显降低模型大鼠AWR评分（P＜ 0.01），明显升高模型大鼠尿D-木糖排泄率（P＜ 0.05），增加模型大鼠进入开臂次数和开臂滞 留时间百分比（P＜ 0.01），显著降低血清皮质醇水平（P＜ 0.01），明显降低大鼠DRG神经元上Nav1.8通道受体mRNA表达水平（P＜ 0.01）。结论 康泰胶囊能抑制应激引 起的内脏高敏感IBS大鼠DRG神经元上的Nav1.8通道受体表达，从而降低结肠背根神经元兴奋性，是其治疗IBS的作用机制之一。

Objective To observe the effect of Kangtai capsule on voltage-gated sodium channel Nav1.8 in dorsal root ganglion neurons of the rats with visceral hypersensitivity，and to investigate its therapeutic mechanism for irritable bowel syndrome（IBS）. Methods The rat model of visceral hypersensitivity was established by chronic unpredicted mild stress，and the visceral sensitivity to colorectal balloon distention（CRD） was measured by abdominal withdrawal reflex（AWR） scores，D-xylose excretion rate，anxiety behavior testing and serum hydrocortisone level. Real-time polymerase chain reaction（RT-PCR） was applied to measure Nav1.8 mRNA expression level. Results Kangtai capsule had obvious effect on decreasing AWR scores，elevating D-xylose excretion rate（P＜ 0.01），increasing the times for rat entering the open arms and the percentage of time staying in the open arms（P＜ 0.01），and decreasing serum hydrocortisone level and Nav1.8 mRNA expression level in the dorsal root ganglia of visceral hypersensitivity rats（P＜ 0.01）. Conclusion Kangtai capsule has an effect on inhibiting Nav1.8 mRNA expression in colonic colonic dorsal root ganglia of IBS rats with visceral hypersensitivity，thus to decrease neuronal excitability，which may be one of its therapeutic mechanism for IBS.

R285.5

广东省自然科学基金（S2012010010081）。