C57BL/6J小鼠在构建2型糖尿病模型中体重和非空腹血糖浓度的异常变化

由北京市一实验动物生产单位购入近交系C57BL/6J(B6)和封闭群ICR(3周龄)小鼠,分别以高脂饲料、高脂饲料-3%果糖饮水(实验组)和常规饲料(对照组)喂养6周,实验组腹腔注射链脲佐菌素(STZ,100mg/kg体重),然后以相应饲料继续喂养4周。每周测定小鼠体重,于注射STZ前和注射后每周测定非空腹血糖浓度。研究显示,无论是否补充果糖饮水,B6对照组体重显著高于实验组,而相应周龄的ICR小鼠,实验组体重显著高于对照组。两品系小鼠实验组间体重无差异。注射STZ后,B6实验组血糖浓度均没有达到糖尿病小鼠非空腹血糖浓度的成模标准(11mmol/L),而ICR实验组血糖浓度均达到并超过糖尿病小鼠非空腹血糖浓度的成模标准。研究表明,无论补充果糖与否,ICR小鼠均能成功建模,而B6小鼠建模均失败。因此,ICR小鼠仍是目前应用高脂饲料-STZ联合诱导2型糖尿病模型中经济、有效的候选动物,而B6小鼠在体重和血糖浓度上的异常表现很可能是其遗传背景变化的结果,这尚需进一步研究证实。

Abnormal Change in Body Weight and Non-Fasting Blood Glucose Levels of Mouse Strain C57BL/6J in Generating Type 2 Diabetes Model

The commercially available inbred obesity-prone C57BL/6J (B6) and outbred stock ICR mice (3-week old) purchased from a breeder of Beijing were weaned onto high-fat diet (HFD), HFD-3% fructose water (HFDF) and standard rodent chow, respectively. After exposure to the diets for six weeks, HFD and HFDF fed mice were injected intraperitoneaily with streptozotocin (STZ, 100mg/kg body weight) and kept on the same diet for next four weeks. Body weight was recorded weekly. Non-fasting blood glucose levels of HFD and HFDF fed mice were measured before and after STZ injections. The body weight of HFD-fed and HFDF-fed B6 mice were significantly lower than that of the control, but body weight of HFD-fed and HFDF-fed ICR mice were significantly higher than that of the control. After injection of STZ, blood glucose levels were above the stardardized criterion (11 mmol/L) for the diabetes mouse model in both HFD and HFDF fed ICR mice, but reverse in B6 mice. The type 2 diabetes model was generated successfully in ICR but not in B6 mice, regardless of whether fructose was supplied. The current results indicated that ICR mouse is still a useful and economical strain for HFD-induced/STZ-treated type 2 diabetes model, and that some variation may occur in the genetic composition among B6 mice bred by different breeders.