外源性鼠NGF对大鼠糖尿病神经痛模型中NGF表达及机械痛阈影响的实验研究

目的:探讨外源性鼠神经生长因子(mouse nerve growth factor,mNGF)对大鼠糖尿病神经痛模型中神经生长因子(nerve growth factor,NGF)表达及机械痛阈的影响.方法:将实验大鼠随机分为四组:正常对照组(Contml,n=10)、生理盐水干预组(Saline,n=10)、小剂量mNGF干预组(mNGFl,n=10)和大剂量mNGF干预组(mNGF2,n=10).以链脲佐菌素(SIZ)诱导大鼠糖尿病模型并在制模前及制模后3天和1、2、4周利用yon Frey丝测定大鼠机械痛阈,并通过western Blot方法测定4周时各组大鼠脊髓背角和背根神经节中NGF蛋白水平表达.结果:小剂量和大剂量mNGF干预组在干预2周后,机械痛阚较生理盐水组均有显著提高;小剂量mNGF干预组只在背根神经节使NGF含量显著增加,而大剂量mNGF干预组在背根神经节和脊髓背角均使得NGF含量显著增加.结论:早期合适剂量的外源性mNGF干预可在一定程度上缓解糖尿病大鼠疼痛.

THE IMPACT OF EXOGENOUS MNGF ON NGF EXPRESSION AND MECHANICAL THRESHOLD IN DIABETIC NEUROPATHIC RATS

Objective:To investigate the effect of exogenous mouse nerve growth factor (mNGF) on NGF expression and mechanical threshold in diabetic rats. Methods:40 experimental rats were divided into 4 groups; normal control group ( Control, n = 10 ) , saline-treatment group ( Saline, n = 10 ) , low-dose mNGF-treatment group( mNGFl, n = 10) and high-dose mNGF-treatment group (mNGF2, n = 10). The model of diabetes was induced by the peritoneal injection of streptozocin ( STZ ). Mechanical threshold was assessed using Von Frey filaments, before and 3 days and 1,2,4 weeks after the formation of diabetes model. The NGF expression in dorsal horn and dorsal root ganglion (DRG) was measured by Western Blot at 4 weeks. Results:The mechanical threshold of mNGFl and mNGF2 groups was elevated 2 weeks after treatment, compared with saline group. The NGF expression of mNGFl group was increased in DRG and the NGF expression of mNGF2 group was increased in DRG and dorsal horn. Conclusion;The treatment of exogenous mNGF can relief the pain of diabetic rats.