川芎嗪对脓毒症相关性脑病大鼠海马神经元自噬的影响

Effect of tetramethylpyrazine on autophagy in hippocampal neurons of rats with sepsis-associated encephalopathy

目的 评价川芎嗪对脓毒症相关性脑病大鼠海马神经元自噬的影响.方法 SPF级健康雄性SD大鼠60只,11～14周龄,体重200～240 g,采用随机数字表法分为3组（n=20）：假手术组（Sham组）、脓毒症组（Sep组）和川芎嗪组（TMP组）.采用盲肠结扎穿孔法制备脓毒症模型,Sham组仅做开腹、分离肠段,不进行盲肠结扎穿孔.TMP组于造模前1 h时腹腔注射川芎嗪10 mg∕kg.于造模后12和36 h时随机取10只大鼠行Morris水迷宫实验,随后处死大鼠取海马组织,采用Western blot法检测微管相关蛋白轻链3Ⅰ（LC3Ⅰ）、LC3Ⅱ、Beclin-1和p62的表达,并计算LC3Ⅱ∕LC3Ⅰ比值.结果 与Sham组比较,Sep组和TMP组造模后12和36 h时逃避潜伏期延长,靶象限活动时间比率降低,海马LC3Ⅱ∕LC3Ⅰ比值升高,Beclin-1表达上调,p62表达下调（P〈0.05）;与Sep组比较,TMP组造模后12和36 h时逃避潜伏期缩短,靶象限活动时间比率升高,海马LC3Ⅱ∕LC3Ⅰ比值降低,Beclin-1表达下调,p62表达上调（P〈0.05）.结论 川芎嗪减轻大鼠脓毒症相关脑病的机制与抑制海马神经元自噬有关.

Objective To evaluate the effect of tetramethylpyrazine on autophagy in the hippocam-pal neurons of rats with sepsis-associated encephalopathy. Methods Sixty SPF healthy male Sprague-Daw-ley rats, aged 11-14 weeks, weighing 200-240 g, were divided into 3 groups（n=20 each）using a ran-dom number table： sham operation group（group Sham）, sepsis group（group Sep）and tetrameth-ylpyrazine group（group TMP）. Sepsis was induced by cecal ligation and puncture（CLP）, and group Sham only underwent simple laparotomy. Tetramethylpyrazine 10 mg∕kg was injected intraperitoneally at 1 h before CLP in group TMP. Morris water maze test was performed in 10 rats randomly selected at 12 and 36 h after CLP. Then the rats were sacrificed, and hippocampi were isolated for determination of the expres-sion of microtubule-associated protein 1 light chain 3Ⅰ（LC3Ⅰ）, LC3Ⅱ, Beclin-1 and p62 in hipp-ocampal tissues by Western blot, and the LC3Ⅱ∕LC3Ⅰratio was calculated. Results Compared with group Sham, the escape latency was significantly prolonged, the rate of time spent in the target quadrant was decreased, the LC3Ⅱ∕LC3Ⅰratio was increased, the expression of Beclin-1 was up-regulated, and the expression of p62 was down-regulated at 12 and 36 h after CLP in group Sep and group TMP（P〈0.05）. Compared with group Sep, the escape latency was significantly shortened, the rate of time spent in the target quadrant was increased, the LC3Ⅱ∕LC3Ⅰratio was decreased, the expression of Beclin-1 was down-regulated, and the expression of p62 was up-regulated at 12 and 36 h after CLP in group TMP（P〈0.05）. Conclusion The mechanism by which tetramethylpyrazine reduces sepsis-associated encephalopa-thy is related to inhibiting autophagy in the hippocampal neurons of rats.