1型与2型糖尿病大鼠周围神经病变的比较

目的观察链脲佐菌素(STZ)诱导的1型与2型糖尿病大鼠周围神经病变的区别。方法 SD大鼠分组,每组各10只,腹腔注射STZ建立1型糖尿病(T1DM)模型;高脂高糖饲养6周后按体质量35 mg/kg单次腹腔注射STZ建立2型糖尿病(T2DM)模型;设立正常对照(Con)组。检测不同时间点大鼠的体质量、血糖水平。成模8周后,电子Von Frey仪检测机械痛阈值,热水甩尾试验检测甩尾潜伏期,并取坐骨神经进行病理形态学检查。结果成模后第1、8周,与对照组及T2DM组相比,T1DM组大鼠的体质量显著下降(P<0. 01); T1DM组与T2DM组的血糖均显著高于对照组(P<0. 01); DM组的甩尾潜伏期均较对照组延长(P<0. 01),T2DM组较T1DM组延长更显著(P<0. 05)。DM组的机械痛阈值均较对照组显著降低(P<0. 01),T2DM组较T1DM组降低更明显(P<0. 01); DM组大鼠的坐骨神经有髓神经纤维排列紊乱,轴索肿胀或皱缩,髓鞘密度不均匀,空泡变性,部分神经纤维髓鞘脱失; T2DM组的神经损害程度较T1DM严重。结论 STZ诱导的2型糖尿病大鼠的周围神经病变程度严重于1型糖尿病大鼠。

Comparison of peripheral neuropathy between type 1 and type 2 diabetes mellitus rats

Objective To observe the difference between type 1 and type 2 diabetic peripheral neuropathy in rats induced by streptozotocin (STZ). Methods SD rats(10 rats in each group),common diet for 6 weeks to establish type 1 diabetes mellitus (T1DM) model by single intraperitoneal injection of STZ,high fat and high sugar diet for 6 weeks to establish type 2 diabetes mellitus (T2DM) model by single intraperitoneal injection of 35 mg/kg 2% STZ. The normal control group (Con) is also established. The body weight and blood sugar were measured at different time. The mechanical withdrawal threshold was tested by electronic Von Frey instrument and hydrothermal tail-flick test was also conducted before death. The sciatic nerve pathology was examined. Results After 1st,8th weeks of diabetes,compared with Con group and T2DM group,the body weight in T1DM group significantly decreased (P<0.01). The blood glucose in T1DM group and T2DM group was significantly higher than Con group (P<0.01). The tail flick latencies in DM groups were longer than that of Con group (P<0.01). The numerical value in T2DM group was longer than that in T1DM group (P<0.05). The threshold of mechanical pain in DM groups were significantly lower than that in Con group (P<0.01),and the decrease in T2DM group was more obvious than that in T1DM group (P<0.01). In DM groups,the myelinated nerve fibers in the sciatic nerve were arranged in disorder,with axonal swelling or shrinkage,uneven density of myelin sheath,vacuolar degeneration and partial myelination of nerve fibers. The degree of nerve damage in T2DM group was more severe than that of T1DM. Conclusions The degree of peripheral neuropathy in type 2 diabetic rats induced by STZ is more severe than that of type 1 diabetic rats.