2型糖尿病大鼠周围神经病变的观察

The study of diabetic peripheral neuropathy in type 2 diabetic rats

目的研究高脂高糖喂养加小剂量链脲佐菌素诱导的2型糖尿病大鼠周围神经病变(DPN)的特点。方法 SD雄性大鼠高脂高糖喂养并腹腔注射STZ(35mg/kg)制备2型糖尿病大鼠模型。造模10周后处死大鼠,测定血清中血脂、血糖水平;取坐骨神经在电镜下进行组织学观察,测定坐骨神经组织中MDA与GSH-Px,并在处死之前检测各组大鼠坐骨神经的传导速度。结果糖尿病模型组大鼠与正常对照组相比血糖增高(P<0.01),体重下降(P<0.01),甘油三酯、总胆固醇及低密度脂蛋白明显升高(P<0.01),坐骨神经传导速度明显减慢(P<0.01);大鼠坐骨神经中MDA水平明显高于正常组(P<0.01),而GSH-Px水平明显低于正常对照组(P<0.01),坐骨神经形态学有明显的损伤反应。结论 2型糖尿病大鼠造模10周后出现周围神经结构和功能损伤,氧化应激可能是导致神经病变发生的机制之一。

Objective To study the feasibility of the high-sucrose-high-fat diet and injected with the low dose STZ induced the model of type 2 diabetic rats,and observed the characteristic of diabetic peripheral neuropathy.Methods SD rats fed with high-sucrose-high-fat diet,and injected with a low dose of STZ（35mg/kg） into abdominal cavity to induce hyperglycemia.The rats were killed in 10th week,and then the levels of blood fat and blood sugar in the blood scrum were detected.The sciatic nerve was taken out for which was observed by Morphometric evaluation under transmission electron microscope.The content of MDA and GSH-Px in sciatic nerve was detected and the speed of conduction in sciatic nerve was measured before being killed.Results There was a raising up tendency in level of blood glucose and decline in level of weight of model-control group（P0.01）.Compared with the normal group,triglycerides,cholesterol and low density lipoprotein in rats of the model group was significantly increased.The sciatic nerve conduction velocity was significantly slow in rats of model group（P0.01）.MDA in sciatic nerve of the rats in model group was significantly increased（P0.01）,but the SOD in sciatic nerve was obviously lower than that in the normal-control group,and there was obvious reactions to the damage in model group.Conclusion The damages to structure and function of peripheral nerves in type 2 diabetic rats is found at advanced stages of DPN.Oxidative stress is the key link to cause occur and development of DPN.