糖尿病性神经痛大鼠脊髓背角突触数量的体视学研究

Stereological study on the synaptic number in the rat spinal dorsal horn with painful diabetic neuropathy

目的:探讨糖尿病性神经痛(painful diabetic neuropathy,PDN)大鼠脊髓背角突触数量的变化。方法:10只健康成年雄性SD大鼠,随机分为两组(n=5):PDN组和对照组(C组)。PDN组采用腹腔注射6%STZ 60 mg/kg建立糖尿病大鼠模型,C组腹腔注射等容生理盐水。注射后72 h测定空腹血糖(FBG),以FBG>11.1 mmol/L为糖尿病建模成功。注射STZ前1 d及血糖升高后第4、7、14、28天分别测定大鼠的机械痛阈。第28天测痛后取L5段脊髓,进行突触素免疫组织化学染色,采用光学体视框交替计数一侧脊髓背角内突触的数量。结果:PDN组大鼠FBG均达糖尿病诊断标准,自FBG升高后4 d开始痛阈降低,至28 d时未恢复。与C组比较,PDN组L5节段脊髓背角内突触数量增加(P<0.05)。结论:PDN大鼠脊髓背角突触数量增加,突触数量增加可诱导PDN的发生。

Objective：To investigate the plasticity change of the synaptic number in the rat spinal dorsal horn with painful diabetic neuropathy. Methods ： 10 healthy adult male SD rats were randomly divided into 2 groups （ n = 5 ） ： the PDN group and the control group. Rats in the two groups were intraperitoneally injected with 6% STZ 60mg/kg or normal saline respectively. 72 hours after injection,fasting blood glucose （FBG） were measured, FBG 〉 11.1 mmol/L were considered a successful diabetes mellitus model. 1 day before injection and4,7,14,28 days after increasing of FBG, the mechanical pain threshold were measured. 28 days after increasing of FBG,the L5 segment of spinal cord were separated and stained with synaptophysin immunohistochemisty. The numerical density of synapses in the spinal dorsal horn was estimated respectively. Results：In the PDN group, FBG rose after injection of STZ, and the pain threshold decreased 4 days after increasing of FBG. Compared to control group,numerical density of synapses increased significantly in the spinal dorsal horn in the PDN group （ P 〈 0. 05 ）. Conclusion ： The rat model of PDN is associated with increase of the synaptic numbers in the spinal dorsal horn of L5 segment.