链脲佐菌素诱导大鼠糖尿病周围神经痛模型探讨

Discussion of diabetic peripheral neuropathic pain model of Sprague-Dawley rats induced by streptozotocin

目的探讨链脲佐菌素（STZ）诱导Sprague Dawley（SD）大鼠糖尿病周围神经痛（DNP）模型的最佳造模方法。方法将30只体质量180-220 g的SD雄性大鼠随机分为6组,每组5只。空白对照组大鼠腹腔注射等剂量枸橼酸缓冲液,A、B、C、D、E组大鼠腹腔分别注射15、30、45、60、75 mg·kg-1STZ,造模前1 d、造模后24 h及1、2、3、4周空腹24 h后测定血糖水平和神经痛功能指标热痛阈和机械痛阈。结果造模后1、2、3、4周,C、D、E组大鼠血糖水平高于空白对照组（P〈0.05）。造模后2、3、4周B、C、D、E组大鼠体质量显著低于空白对照组（P〈0.01）,而A、B、C、D、E组大鼠的饮食量和饮水量高于空白对照组（P〈0.05）;E组大鼠成活率低于空白对照组、C组和D组（P〈0.05）。注射STZ前各组大鼠甩尾潜伏期（TFL）、热缩足潜伏期（TWL）、机械痛阈（MWT）比较差异均无统计学意义（P〉0.05）。造模后2、3、4周A、B、C、D、E组大鼠TFL、TWL、MWT较空白对照组低（P〈0.05）。随着STZ注射剂量的增大,TFL、TWL、MWT逐渐降低,A、B、C、D、E组大鼠组间比较差异有统计学意义（P〈0.05）。结论 STZ剂量在45~60 mg·kg-1是建立大鼠DNP模型最佳剂量范围,痛敏反应明显,成功率高。

Objective To explore the best way to establish the diabetic peripheral neuropathic pain （DNP） model of Sprague Dawley （SD） rats induced by streptozotocin （STZ）. Methods Thirty male SD rats （the weight 180 -220 g） were ran- domly divided into six groups,five rats in each group. The rats in blank control group were given the same volume of citrate buffer solution by intraperitoneal injection; the A, B, C, D and E group was respectively injected with STZ 15,30,45,60, 75 mg·kg-1. At the time of one day before and after injection, and one, two, three and four weeks after injection, the fasting blood glucose （24 h FBG） and the index of the neuralgia function, including thermal withdrawal latency （TWL） and mechanical withdrawal threshold （MWT） were detected. Results One, two, three and four weeks after building the models, the level of 24 h FBG was higher in C ,D,E group than that in blank control group（P 〈0.05）. Two,three and four weeks after building the mod- els, the body weight of B, C, D, E group was lower than that of blank control group （ P 〈 0.01 ）, while the amount of food and water consumption was higher in A, B, C, D, E group than that in blank control group （ P 〈 0.05 ）. But the rate of survival in E group was lower than that in blank control group, C and D group （ P 〈 0.05 ）. There was no significant difference in tail-flick latency （TFL）, TWL and MWT among the groups before injecting STZ（P 〉 0.05 ）. The TFL, TWL and MWT in A, B, C, D and E group was lower than that in blank control group two, three and four weeks after building the models （P 〈 0.05 ）. With the increase of STZ injection dose ,TFL,TWL and MWT gradually reduced ;there was significant difference among the A, B, C, D, E group （P 〈 0.05）. Conclusion The DNP model of SD rats induced by the 45 - 60 mg·kg-1 dose of STZ is the optimum model. The pain hypersensitivity response is obvious and it can obtain a higher success level.