筋脉通对糖尿病大鼠周围神经组织神经生长 因子表达的影响

目的：观察中药复方筋脉通对链脲佐菌素诱导的糖尿病大鼠坐骨神经神经生长因子(nerve growth factor，NGF )mRNA和蛋白表达的影响。方法：采用链脲佐菌素一次性腹腔内注射大鼠的方法造模，简单随机分为模型对照组、筋脉通小剂量、中剂量和大剂量组、神经妥乐平组及正常对照组。成模后即开始灌胃给药，筋脉通低、中、高组分别按成人剂量的5，10，20倍给药；神经妥乐平组按成人剂量的10倍给药。模型组和正常组予灌服蒸馏水。所有实验大鼠于灌胃16周后处死。检测各组治疗前及治疗后4，8，12，16周的体重和血糖变化，并进行热水甩尾试验和机械痛阈检测，采用实时荧光定量PCR法检测坐骨神经NGF mRNA的表达，免疫组化染色法测定坐骨神经NGF蛋白的表达。结果：糖尿病大鼠血糖值均显著高于正常组(P<0.01)；各治疗组血糖在各时间点与模型组相比无明显差异。造模及灌胃前后，各组大鼠之间的体重无明显差异。模型组和各治疗组较正常组甩尾潜伏期延长、机械痛阈下降，坐骨神经NGF mRNA和蛋白表达减少(P<0.05或P<0.01)。与模型组相比，筋脉通中剂量组与神经妥乐平组的甩尾潜伏期显著缩短、痛阈值显著升高，坐骨神经NGF mRNA和蛋白表达增加(P<0.05或P<0.01)。筋脉通中剂量组与神经妥乐平组相比无显著差异。结论：筋脉通能够增加糖尿病周围神经病变大鼠坐骨神经NGF mRNA的转录和蛋白的表达。

Effects of Jinmaitong capsule on nerve growth factor in diabetic rats

Objective: To study the effects of Jinmaitong Capsule (JMT) on the expression of NGF and NGF mRNA in STZ-induced diabetic rats. Method: Fifty SZT-induced diabetic rats were randomly divided into 5 groups including model group, low-dose JMT group (treated with JMT similar to the quintupling dose of adult recommended dosage), middle-dose JMT group (treated with JMT similar to the decuple dose of adult recommended dosage), high-dose JMT group (treated with JMT similar to the twenty-fold dose of adult recommended dosage) and Neurotropin group (treated with Neurotropin similar to the decuple dose of adult recommended dosage). Ten normal rats matching with weight and age served as normal control group. All rats were given intragastric administration for 16 weeks and then killed. Body weight and blood glucose were detected before and at the 4, 8, 12, 16 th week after treatment. The hydrothermal tail-flick and pain threshold to mechanical stimulation with Von Frey filament were carried out before death. The expression of NGF and NGF-mRNA in sciatic nerve were detected by SABC immunohistochemical method and real-time fluorogenetic quantitative PCR respectively. Result: The blood glucose levels of STZ-DM rats were much higher than those of normal rats (P<0.01). In all the treated groups, there were no significant differences among them compared each other or compared with model group. And it got the same result when concerning about body weight no matter how the rats were dealt with. Hydrothermal tail-flick test: The tail-flick latency of STZ-DM rats were much longer than those of normal rats (P<0.01 or P<0.05). Compared with model group, the time shortened significantly in low, middle-dose of JMT groups and Neutrophin group. Compared with normal group, the pain thresholds of model group decreased extremely (P<0.01). Compared with model group, the threshold values of low-dose, middle-dose JMT group and neutrophin group raised strikingly (P<0.05). The levels of NGF-mRNA expression in STZ-DM rats were much lower than those of the normal rats (P<0.01). Compared with model group, NGF-mRNA expression of middle-dose JMT group and Neurotropin group up-regulated noticeably (P<0.01). The integrated option density of NGF expression in STZ-DM rats was much lower than the normal (P<0.01 or P<0.05). And the levels of NGF in all the treated groups increased notably compared with model group (P<0.05 or P<0.01). There were no significant differences among middle-dose JMT group and Neutrophin group. Conclusion: Traditional Chinese medicine JMT could up-regulate the expression of NGF and NGF-mRNA in sciatic nerve.