利用不同升糖指数饮食构建2型糖尿病大鼠血糖波动模型的实验研究

目的尝试利用不同升糖指数(GI)饮食构建2型糖尿病大鼠血糖波动模型。方法应用高糖高脂饲料喂食联合一次性腹腔注射链脲佐菌素构建2型糖尿病(T2DM)大鼠,根据血糖和体重水平将其分为高GI饮食组(波动组)和低GI饮食组(稳定组),然后采用定时投食的方法,高GI组喂以高GI饲料,低GI组喂以低GI饲料。7天后经尾静脉采血法测定各组大鼠三餐前及餐后2h血糖,连续测定5天后,观察大鼠一般情况,应用ELISA法检测空腹血糖(fasting blood glucose,FBG)、血清总胆固醇(TC)、甘油三酯(TG)、胰高血糖素(glucagon)和胰岛素(insulin)水平并计算胰岛素敏感度指数(ISI)、最大血糖波动幅度和平均血糖波动幅度。结果与正常组相比,稳定组和波动组糖尿病大鼠体重、血清FBG、TC和TG水平均显著升高(P<0.05或P<0.01),但两组差异无统计学意义;波动组和稳定组大鼠胰高血糖素和胰岛素均显著升高,ISI显著降低(P<0.01),而两组间差异无统计学意义;稳定组和波动组糖尿病大鼠MAGE和LAGE水平均明显升高(P<0.01);与稳定组相比,波动组MAGE和LAGE水平明显增加(P<0.01)。结论在不影响大鼠整体血糖水平的情况下,高GI饮食组糖尿病大鼠比低GI饮食组大鼠具有更加明显的血糖波动。运用高GI饮食和低GI饮食喂养2型糖尿病大鼠可以成功构建2型糖尿病大鼠血糖波动模型,且该模型可保证2型糖尿病大鼠血糖相对稳定。

Establishment of Type 2 Diabetes Mellitus Rats Model with High Blood Glucose Fluctuation using Different Glucose Index Diet.

Objective To establish type 2 diabetes mellitus (T2DM) rats model with high blood glucose fluctuation using different glucose index diet. Methods The T2DM models were induced by intraperitoneal injection of streptozotocin plus high fat and high caloric laboratory chow. Then they were divided into high GI diet group and low GI diet group according to glucose level and body weight level fed with the fixed time and fixed location. The fasting blood glucose and postprandial blood glucose were measured for five days. General condition, the level of fasting blood glucose (FBG), serum total cholesterol (TC), triglyceride (TG), glucagon and insulin were measured, insulin sensitivity index (ISI), largest amplitude of glycemic excursions (LAGE) and the mean amplitude of glycemic excursions (MAGE) were calculated. Results In comparison with Normal group, levels of body weight, serum FBG, TC and TG in high GI diet group and low GI diet group were all significantly increased (P<0.05, P<0.01), however, there was no significant difference between those two groups. In comparison with Normal group, levels of glucagon and insulin in high GI diet group and low GI diet group were all significantly increased (P<0.01), meanwhile ISI was decreased obviously (P<0.01). However, there was no significant difference between high GI diet group and low GI diet group. In comparison with normal group, levels of MAGE and LAGE in high GI diet group and low GI diet group were all significantly increased (P<0.01), and there was significant difference between high GI diet group and low GI diet group (P<0.05, P<0.01). Conclusion Without impacting the levels of blood glucose, there appeared more obvious blood glucose fluctuation in high GI diet T2DM rats than low GI diet T2DM rats. We can establish T2DM rat model with high blood glucose fluctuation and relative constant high blood glucose by feeding high GI diet and low GI diet successfully.