树鼩2型糖尿病加剧缺血性脑损伤的可能机制

目的 建立树鼩2型糖尿病（T2DM）合并脑缺血模型，探讨代谢异常加剧缺血性脑损伤的可能机制。 方法 将36只健康成年树鼩随机分为4组，即对照组、脑缺血组、T2DM组及T2DM +脑缺血组(每组n=9)。采用高脂饲养联合链脲佐菌素（STZ）注射建立实验性糖尿病模型，通过光化学反应诱导树鼩局部血栓形成，以临床症状最突出的缺血后24 h作为观察的时间点，通过血清生化指标的检测了解机体代谢状态，采用2，3，5-氯化三苯基甲氮唑（TTC）、HE染色及透射电子显微镜观察超微结构对缺血性脑损伤进行评价。 结果 树鼩T2DM和T2DM合并脑缺血组树鼩的体重有所降低［(120.29±13.82) g］，但差异无统计学意义，而血糖（FBG）、总胆固醇（TC）、低密度脂蛋白固醇（LDL-C）及甘油三酯（TG）明显升高，分别为（26.75±10.60）mmol/L、（7.40±3.26) mmol/L、（2.93±0.70）mmol/L、（1.93±0.63）mmol/L（P<0.05）和（32.29±6.08）mmol/L（7.80±3.41) mmol/L、（3.06±0.95）mmol/L和（1.73±0.29）mmol/L，（P<0.01）； 血清C-反应蛋白（CRP）水平明显升高［（1.43±0.53）mg/L，P<0.01］。糖尿病树鼩合并脑缺血时上述指标的改变更为明显，神经元受损及脑梗死面积明显增加［（19.56±1.25）%,P<0.01］。 结论 T2DM树鼩代谢异常可加剧缺血性脑损伤，其机制可能与高血糖及CRP协同作用引起的炎症反应有关。

Mechanism of metabolic disorders aggravated ischemic brain injury in tree shrews of type 2-diabetes mellitus

Objective To explore the mechanism of metabolic abnormality or without exacerbating ischemic brain injury by establishing tree shrew models with type 2 Diabetes mellitus (T2DM), combined with the cerebral ischemia or not. Methods Thirty-six tree shrews were randomly devided into 4 groups: control, ischemia, T2DM and T2DM combined with cerebral ischemia groups. The experimental diabetes model was established by the use of high lipid breeding combined with streptozocin (STZ) injection in tree shrews. The local cerebral thrombosis was induced by photochemical reaction in tree shrews. The metabolic status of the body was measured by serum biochemical markers. 2,3,5-triphenyl tetrazolium chloride(TTC) staining, HE staining and trunsmission electron microscopy were used to observe the changes of the body’s metabolic status at hour 24 after the most prominent clinical manifestations. Results The body weight of tree shrews in the T2DM and T2DM combined with cerebral ischemia groups was decreased (120.29±13.82)g, but there was no statistical difference(P>0.05). Fasting blood glucose (FBG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) were significantly higher, and their values were (26.75 ± 10.60）mmol/L,（7.40 ± 3.26) mmol/L,（2.93±0.70）mmol/L,（1.93±0.63）mmol/L, respectively(P<0.05) in T2DM group, and (32.29±6.08) mmol/L, (7.80 ± 3.41) mmol/L, (3.06 ± 0.95) mmol/L and (1.73 ± 0.29) mmol/L, respectively(P<0.01) in T2DM combined with cerebral ischemia group. Serum C-reactive protein (CRP) level was obviously increased (1.43± 0.53) mg/L(P<0.01). The changes of the above indicators were more obvious when T2DM was combined with cerebral ischemia and the neurons were damaged and the area of cerebral infarction was significantly increased (19.56 ±1.25) % (P<0.01). Conclusion The metabolic abnormality of T2DM tree shrews can aggravate ischemic brain injury, and its mechanism may be related to the inflammatory response caused by the synergistic effect of CRP.