氯喹对大鼠脑缺血再灌注自噬相关蛋白的影响

目的　探讨氯喹对大鼠脑缺血再灌注自噬相关蛋白的影响及其机制。 方法　取75只大鼠随机分为假手术组（Sham），模型组（Model），氯喹（CQ)20、40、60 mg/kg组，每组15只。应用线栓法使右脑中动脉栓塞（MCAO)，栓塞2 h。3个药物组于栓塞后立即腹腔注射CQ 20、40、60 mg/kg，其余各组注射2 ml 0.9%氯化钠。再灌注24 h后，采用神经功能缺损评分、TTC染色判断模型是否制作成功，采用免疫荧光和免疫印迹法检测大鼠脑自噬相关蛋白的表达。 结果 ① Sham组, Model组, CQ 20、40、60 mg/kg组神经功能缺损评分，分别为0、2.67±0.49、2.93±0.26、2.40±0.51及1.93±0.70。通过TTC染色与Model组比较梗死面积，CQ 20 mg/kg组增大，CQ 40 mg/kg组无明显变化，CQ 60 mg/kg组减小。②免疫荧光和免疫印迹结果显示各组均有蛋白(Atg5、Atg7、Beclin1、Atg12）表达，与Model组比较,其中Sham组仅有极少量表达（P<0.05)，CQ 20 mg/kg组表达量无明显差异,CQ 60 mg/kg组的表达量明显减少（P<0.05)。 结论　氯喹对大鼠脑缺血再灌注损伤有双重作用，低剂量20 mg/kg加重损伤，高剂量60 mg/kg减轻损伤。其机制可能与某些脑自噬相关蛋白表达的量有关。

Effects of chloroquine on the expressions of autophagy related proteins after focal cerebral ischemia-reperfusion in rats

Objective To investigate the effects of chloroquine on the expressions of autophagy related proteins after focal cerebral ischemia-reperfusion in adult rats. Methods A total of 75 healthy SD rats were randomly allocated to sham-operation, model and chloroquine(CQ) 20,40 and 60 mg/kg groups. A model of middle cerebral artery occlusion (MCAO) for 2 h was induced by suture method. The CQ 20,40 and 60 mg/kg groups were injected intraperitoneally immediately following MCAO in the 3 medication groups. Neurological deficit scores and TTC staining were evaluated, and then the expressions of autophagy related proteins in area of cerebral ischemia-reperfusion were analyzed by immunofluorescence and Western blot technique at 24 h after reperfusion. Results　①Neurological deficit scores in the sham-operation, model, CQ 20, 40 and 60 mg/kg groups were 0, 2.67±0.49, 2.93±0.26, 2.40±0.51 and 1.93±0.7 respectively. Compared with the infarction area of the model group by TTC staining, the CQ 20 mg/kg group was significantly increased, the CQ 40 mg/kg group was almost like the model group，the CQ 60 mg/kg group was significantly decreased. ② Compared with the model group, the results of immunofluorescence and Western blot technique showed only a trace expressions of proteins(Atg5, Atg7, Beclin1 and Atg12 ) in the sham operation group (P<0.05), and the same pattern of expressions were observed in the CQ 20 mg/kg group. However there was significantly reduced expressions in the CQ 60 mg/kg group (P<0.05). Conclusion　The CQ have has two fold effects, i.e., the CQ 20 mg/kg group can aggravate the damage, whereas the CQ 60 mg/kg can alleviatereduce the damage. The mechanism of CQ in the prevention and treatment of cerebral ischemia-reperfusion injury in rats may be associated with the dose of the expressions of some autophagy related proteins.