糖尿病周围神经病变大鼠疼痛模型的建立

AN ANIMAL MODEL OF PAINFUL DIABETIC PERIPHERAL NEUROPATHY IN RATS

摘要:

目的：探讨建立糖尿病周围神经病变大鼠疼痛模型的可行性，为糖尿病周围神经病变疼痛的发生机制及治疗提供稳定的研究基础。方法：24只SD大鼠随机分为对照组和模型组，模型组腹腔注射60mg／Kg链尿佐菌素。造模前、造模后48小时、6周取尾静脉血测血糖；造模前、造模后1、2、3、4、5、6周测定大鼠50％缩爪机械阈值（PWT）；造模后6周，透视电镜观察腓肠神经超微结构。结果：造模后48h模型组随机血糖高于16．7mmol／L比率为83．3％，与对照组比较，模型组48h,6周时血糖明显增高（P〈0．01）；造模后3周模型组PWT明显低于正常对照组（P〈0．05），5周时PWT下降达高峰（P〈0．01）；模型组腓肠神经有髓纤维普遍出现明显脱髓鞘，髓鞘板层排列紊乱、肿胀。结论：腹腔注射链尿佐菌素建立痛性糖尿病大鼠模型成功率高、简单易行、模型稳定、外周神经病变确切。

Abstract:

Objective: To investigate the feasibility of establishing an animal model with painful diabetic peripheral neuropathy in rats. Methods: Twenty-four SD rats were randomly divided into controlled group and diabetic group. Rats in diabetic group were given intraperitoneally streptozotocin (STZ) injection at a dose of 60 mg/Kg, while the same volume of saline was given in controlled rats. Blood samples from tail vein were collected for determination of the glucose level at 48 h, and 6 W after STZ or saline injection respectively. Von Frey filaments were applied to measure the 50% paw withdraw threshold(PWT) by stimulating the hind paw at before and 1, 2, 3, 4, 5, 6 W after injection. The microstructure of sural nerve were observed via electronic microscope at 6 W after injection. Results: The ratio of random blood sugar was higher than 16.7 mmol/L reached 83.3% after STZ injection. The level of blood sugar in diabetic group was significantly higher as compared to that of controlled group at 48 h, 6 W after STZ injection. 50% PWT was decreased dramatically in diabetic rats at 3 W after STZ injection(P<0.05) and at 4,5,6 W after STZ injection(P<0.01). Obvious demyelinated procedure in sural nerve was observed in diabetic group, accompanied by edema and disordered array of myelin. Conclusion: Intraperitoneal injection of STZ at a dose of 60 mg/Kg established an animal model with painful diabetic peripheral neuropathy in rats.