肠系膜上动脉灌注高氧液对家兔肠缺血-再灌注损伤的保护作用

Protective effects of hyperoxygenated solution infusion via superior mesenteric artery on intestinal ischemia-reperfusion injury in rabbits

目的探讨术中肠系膜上动脉(SMA)灌注高氧液对家兔肠缺血再灌注损伤的保护作用及机制。方法健康家兔32只,随机均分为假手术组(S组)、缺血再灌注组(I组)、高氧液灌注组(H组)和灌注对照组(C组)。开腹夹闭SMA1h造成缺血,松夹再灌注2h制作肠缺血再灌注模型。H组在缺血期经SMA以20ml·kg-1·h-1恒速灌注高氧液1h,C组则采用同样方法输入等容量的5%葡萄糖液。再灌注2h后分别测定各组肠组织丙二醛(MDA)含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPX)活性;观察光镜下各组肠粘膜组织形态学改变;测定肠粘膜组织ATP含量,并测定肠道的氧摄取率。结果小肠缺血再灌注后,肠组织MDA含量明显升高,SOD、CAT和GPX活性明显下降,光镜下肠粘膜损伤严重,肠粘膜组织ATP含量及肠道的氧摄取率均明显下降。I组与C组各参数差异无显著意义。与I组和C组相比,H组肠组织MDA含量明显降低(P<0.01),SOD、CAT和GPX活性明显升高(P<0.05),光镜下肠粘膜损伤明显减轻,肠粘膜组织ATP含量及肠道的氧摄取率均明显增加(P<0.05,P<0.01)。结论术中经SMA灌注高氧液是一种安全有效的小肠保护方法,这与高氧液中的高氧分压有关,并通过增强抗氧化酶的活性减轻肠缺血再灌注损伤。

Objective To investigate the protective effects and the probable mechanism of hyperoxygenated solution （HOS） infusion via superior mesenteric artery （SMA） on intestinal ischemia-reperfusion （I/R） injury in rabbits. Methods Thirty two rabbits were randomly divided into sham operation group （S）, ischemia-reperfusion group（I）, hyperoxygenated solution infusion group （H） and infusion control group （C）. Intestinal I/R model was established by clamping SMA with an atrau matic vascular clamp for 1 h, and followed by reperfusion for 2 h. In group H, HOS was administered via SMA immediately after clamping at the rate of 20 ml·kg^-1·h^- 1 for 1 h, and in group C 5% glucose solution was used instead of HOS. After 2 h of reperfusion,MDA content, SOD, CAT and GPX activities in intestinal tissues were detected respectively. The morphological changes of intestinal tissue were observed under optical microscope. Mucosal ATP content and intestine oxygen extraction （Oext） were also determined. Results After I/R, the intestinal tissue MDA levels increased significantly, and the activities of SOD, CAT and GPX decreased markedly. Obvious morphological changes were observed in intestinal mucous membrane, and mucosal ATP content and Oext were also decreased significantly in group I. There were no differences in all parameters between group I and C. Compared with group I and C, the intestinal tissue MDA levels in group H were significantly lower （P〈0.01）, and the activities of SOD, CAT and GPX in group H were significantly higher （P〈0.05）, and there was less degree of injury of mucous membrane in group H. The mucosal ATP content and intestine Oext were significantly higher in group H than those in group I （P〈0.05, P〈0.01）. Conclusion Intraoperative infusion of HOS via SMA can protect small intestine from I/R injury by supplying adequate oxygen and increasing the activities of SOD, CAT and GPX.