川芎嗪对大鼠脑缺血再灌注后细胞凋亡及caspase 12表达的影响

Effects of tetramethylpyrazine on expression of caspase 12 and apoptosis in rats with focal cerebral ischemia and reperfusion

目的研究川芎嗪对大鼠脑缺血再灌注后细胞凋亡及天冬氨酸特异性半胱氨酸蛋白酶12(caspase 12)表达的影响。方法将48只SD大鼠随机分为假手术组(S)、脑缺血再灌注组(I/R)、川芎嗪低剂量组[10 mg/(kg·d),I/R+TMP组]、川芎嗪高剂量组[30 mg/(kg·d),I/R+TMP组],各组治疗7 d,1次/d,腹腔注射,S组和I/R组给予同剂量生理盐水,7 d后线栓法制备脑缺血再灌注模型,缺血2 h再灌注22 h。检测各组大鼠神经行为学评分、TTC法测定脑梗死体积、TUNEL法检测细胞凋亡、western blot印迹检测GRP78及caspase 12蛋白表达含量。结果与S组相比,I/R组神经行为学评分较高,神经细胞凋亡及脑梗死体积增高,GRP78及caspase 12的蛋白表达含量上升(P<0.05);与I/R组相比,川芎嗪组可改善大鼠脑神经行为学评分,降低脑梗死体积及细胞凋亡百分率、抑制GRP78及caspase 12的蛋白表达(P<0.05)。结论川芎嗪对大鼠脑缺血再灌注损伤具有保护作用,其机制与其抑制细胞凋亡及caspase 12的表达有关。

Objective To observe the effects of tetramethylpyraxine （TMP） on expression of caspase 12 and apoptosis in rats with focal cerebral isc.hemia and reperfusion. Methods Forty - eight SD rats were randomly divided into sham operation group （ S group）, cerebral ischemia reperfusion group （ I/R group）, I/R ＋ TMP1 group （ 10 mg/kg ·d）, and I/R ＋ TMP2 group （30 mg/kg·d）. Rat acute cerebral ischemia reper- fusion injury was made through 2 hours of temporary middle cerebral artery occlusion followed with 22 hours of reperfusion. The rats were then trea- ted for 7 days. S group and/JR group were given the same dose of normal saline. The volume of cerebral infarction, apoptosis, protein expressions of GRP78 and caspase 12 were analyzed by Trc, TUNEL and western blot, respectively. Neurebehavioral score was also determined. Results Compared with the S group, neural behavior score, apoptosis and cerebral infarction volume in I/R group were increased, the protein expressions of GRP78 and caspase 12 in I/R group were significantly increased （ P 〈0.05）. Compared with the I/R group, neural behavior score, apoptosis and cerebral infarction volume was lower, protein expressions of GPJr/8 and caspase 12 in I/R ＋ TMP group decreased dramatically （ P 〈0.05 ）. Conclusion TMP can attenuate cerebral ischemia reperfusion injury, and the protective mechanism may be partly through regulating caspase 12 gene expression and reducing neuronal apoptosis.