摘要目的 评价羟考酮对大鼠肠缺血再灌注损伤的影响及自噬在其中的作用.方法 健康成年雄性SD大鼠24只,6～9周龄,体重180～220 g,采用随机数字表法分为4组(n=6):假手术组(S组)、肠缺血再灌注组(I/R组)、羟考酮组(O组)和羟考酮+自噬抑制剂3-甲基腺嘌呤组(O+3-MA组).采用夹闭肠系膜上动脉1h再灌注2h的方法制备肠缺血再灌注损伤模型.O组和O+3-MA组于缺血前15 min时尾静脉注射羟考酮0.5 mg/kg.O+3-MA组于缺血前10 min腹腔注射3-MA 30mg/kg.于缺血前即刻胃内灌注异硫氰酸荧光素标记的右旋糖酐(FITC-dextran).再灌注2h时心尖穿刺采集血样,测定血清FITC-dextran浓度;于再灌注2h时心尖穿刺采集血样,ELISA法测定血清TNF-α、IL-1β浓度;取小肠组织,观察病理学变化并行Chiu评分;Western blot法测定紧密连接蛋白occludin、自噬相关蛋白Beclin-1和微管相关蛋白1轻链3(LC3)的表达,并计算LC3Ⅱ与LC3 Ⅰ表达比值(LC3Ⅱ/Ⅰ比值).结果 与S组比较,I/R组Chiu评分、血清FITC-dextran、TNF-α和IL-1β浓度、LC3Ⅱ/Ⅰ比值升高,Beclin-1表达上调,occludin表达下调(P＜0.05);与I/R组比较,O组Chiu评分、血清FITC-dextran、TNF-α和IL-1β浓度降低,LC3Ⅱ/Ⅰ比值升高,occludin和Beclin-1表达上调(P＜0.05),O+3-MA组上述指标差异无统计学意义(P＞0.05);与O组比较,O+3-MA组Chiu评分、血清FITC-dextran、TNF-α和IL-1β浓度升高,LC3Ⅱ/Ⅰ比值降低,occludin和Beclin-1表达下调(P＜0.05).结论 羟考酮可减轻大鼠肠缺血再灌注损伤,其机制可能与增强肠组织自噬水平有关.

abstractsObjective To evaluate the effect of oxycodone on intestinal ischemia-reperfusion injury in rats and the role of autophagy.Methods Twenty-four healthy adult male Sprague-Dawley rats,aged 6-9 weeks,weighing 180-220 g,were divided into 4 groups (n =6 each) using a random number table method:sham group (group S),intestinal I/R group (group I/R),oxycodone group (group O) and oxycodone plus autophagy inhibitor 3-methyladenine (3-MA) group (group O+3-MA).Intestinal I/R was induced via clamping the superior mesenteric artery for 1 h,followed by 2-h reperfusion in all the groups except for group S.Oxycodone 0.5 mg/kg was injected via caudal vein at 15 min before ischemia in group O and group O+3-MA.3-MA 30 mg/kg was intraperitoneally injected at 10 min before ischemia in group O+3-MA.Rats were gavaged with fluorescein-isothiocyanate-conjugated dextran (FITC-dextran) immediately before ischemia.Blood samples were collected from the cardiac apex at 2 h of reperfusion to detect the level of serum FITC-dextran.Blood samples were collected from the cardiac apex at 2 h of reperfusion to measure the concentrations of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) in serum by enzyme-linked immunosorbent assay.Small intestinal tissues were obtained at 2 h of reperfusion for examination of the pathological changes and for determination of the expression of occludin,Beclin-1 and microtubule-associated protein 1 light chain 3 (LC3) (by Western blot).Intestinal damage was assessed and scored according to Chiu.The ratio of LC3 Ⅱ expression to LC3 Ⅰ expression (LC3 Ⅱ / Ⅰ) was calculated.Results Compared with group S,the Chiu's score,levels of serum FITC-dextran,TNF-α and IL-1β and LC3 Ⅱ/Ⅰ ratio were significantly increased,the expression of Beclin-1 was up-regulated,and the expression of occludin was down-regulated in group I/R (P＜0.05).Compared with group I/R,the Chiu's score and levels of serum FITC-dextran,TNF-α and IL-1β were significantly decreased,LC3 Ⅱ / Ⅰ ratio was increased,and the expression of occludin and Beclin-1 was up-regulated in group O (P＜0.05),and no significant change was found in the parameters mentioned above in group O+ 3-MA (P＞0.05).Compared with group O,the Chiu's score and levels of serum FITC-dextran,TNF-α and IL-1β were significantly increased,LC3 Ⅱ / Ⅰ ratio was decreased,and the expression of occludin and Beclin-1 was down-regulated in group O + 3-MA (P＜ 0.05).Conclusion Oxycodone can ameliorate intestinal I/R injury,and the mechanism may be related to enhancing autophagy in intestinal tissues of rats.