目的 旨在建立早期糖尿病周围神经病变(diabetic peripheral neuropathy, DPN)大鼠模型。方法 26只雄性SD大鼠经过适应性喂养1周后,分为对照组(n=6)和模型组(n=22)。模型组给予D12451高糖高脂饲料(碳水化合物的热量占比35%,脂肪的热量占比45%)喂养6周诱导胰岛素抵抗,对照组给予普通饲料。随后模型组按体质量给予35 mg/kg的链脲佐菌素(streptozocin,STZ)缓冲液腹腔注射诱导胰腺特异性损伤,对照组给予等量的缓冲液,48 h后测定模型组大鼠的随机血糖,大于16.7 mmol/L即认为2型糖尿病(type 2 diabetes mellitus,T2DM)造模成功。评价T2DM大鼠的一般特征,包括体质量、空腹血糖、糖耐量及胰岛素耐量。定期监测其热痛阈的变化,判断早期DPN出现的时间,最后测定大鼠的坐骨神经传导速率。结果 模型组大鼠经过高糖高脂饮食喂养6周联合STZ腹腔注射后,T2DM造模成功。T2DM组与对照组相比,空腹血糖明显升高(P<0.001),糖耐量及胰岛素耐量均明显受损(分别为P<0.001,P=0.002)。模型建立成功后第17天,T2DM组与对照组相比表现出明显的热痛觉过敏(P=0.004),两组的坐骨神经传导速率差异无统计学意义(P=0.196)。结论 高糖高脂饮食喂养大鼠6周联合35 mg/kg的STZ腹腔注射可成功诱导T2DM模型,表现为一定程度的胰岛素抵抗与胰岛素缺乏,此模型在第17天左右出现早期DPN,其中小纤维的损害早于大纤维。

Objective: To create the early diabetic peripheral neuropathy (DPN) rat model. Me-thods: After one-week adaption, 26 male Sprague-Dawley (SD) rats were divided into two groups, the control group (n=6) and the model group (n=20). High-sucrose/high-fat diet (D12451, 35% of energy from carbohydrate, 45% of energy from fat) was given to the model group for six weeks to induce insulin resistance, meanwhile normal diet was given to the control group. Afterwards, streptozocin (STZ) buffer solution (35 mg/kg bodyweight) was injected into abdomen of the model group to induce specific pancreatic injury, meanwhile an equal amount of buffer solution was given to the control group. Then 48 h later, type 2 diabetes mellitus (T2DM) was supposed to be successfully induced according to the random blood glucose more than 16.7 mmol/L in the model group. Then the basic features of the T2DM rats were evaluated, including body weight, fasting blood glucose (FBG), glucose tolerance (oral glucose tolerance test, OGTT), and insulin tolerance (intraperitoneal insulin tolerance test, IPITT). Subsequently, withdrawal thermal latency (WTL) was measured regularly to determine when the early DPN occurred. Once confirmed, sciatic nerve conduction velocity (NCV) of all the rats was conducted.Results: The T2DM rats were successfully induced in the model group through high-sucrose/high-fat diet for six weeks along with STZ intraperitoneal injection (35 mg/kg bodyweight). When compared to the control group, the T2DM rats had higher FBG (P<0.001), and the glucose tolerance and insulin tole-rance were both damaged (P<0.001 in OGTT, P=0.002 in IPITT). It was on the 17 ^th day when the T2DM rats became much more sensitive to heat stimulus compared to the control group (P=0.004). Meanwhile, the sciatic NCV was conducted. There was no significant difference between the early DPN group and the control group (P=0.196).Conclusion: High-sucrose/high-fat diet for six weeks along with STZ intraperitoneal injection (35 mg/kg bodyweight) could successfully induce T2DM rat model, manifested by a certain extent of insulin resistance and deficiency of insulin secretion. It was about 17 days later when the early DPN emerged. In the early DPN, small fiber neuropathy came out earlier than large fiber neuropathy.