肢体缺血再灌注时大鼠肠系膜微循环的变化

The Changes of Mesentery Microcirculation in Rats with Hind Limbs Ischemia-Reperfusion

目的:观察肢体缺血再灌注(IR)损伤大鼠肠系膜微循环变化,并探讨其意义。方法:实验大鼠随机分为6组(每组10只)进行实验:非缺血对照组(Control组)、缺血4h组(I组)、再灌注20min组(IR20组)、再灌注60min组(IR60组)、再灌注120min组(IR120组)、再灌注200min组(IR200组),用BI-2000医学图像分析系统观察和记录各组肠系膜微循环变化,并分别测定各组血浆前列环素I2(PGI2)、血栓烷A2(TXA2)水平,计算PGI2/TXA2比值。结果:⑴肠系膜微动脉和微静脉管径变化:与Control组比较,I组无显著性变化(P>0.05),IR20组、IR60组明显缩小(P<0.01或P<0.05),IR120组、IR200组显著扩大(P<0.01或P<0.05);⑵肠系膜微动脉和微静脉血流速度变化:与Control组比较,I组无显著性变化(P>0.05),IR20组、IR60组、IR120组、IR200组依次减慢(P<0.01);⑶再灌注后期,出现较严重白细胞黏附、聚集和白微栓的动物数量增加,甚至有微血管出血;⑷血浆PGI2、TXA2含量均于再灌注期先升高后降低,PGI2/TXA2比值于再灌注期降低。结论:大鼠肢体IR损伤时存在肠系膜微循环障碍,其发生可能与血管内皮功能损害、PGI2/TXA2水平失衡有重要关系。

Objective:To investigate the changes of mesenteric microcirculation during ischemia-reperfusion(IR)in the hind limbs of rats as well as to explor the meanings.Method:The experimental rats,which in the model of LIR in routine in our laboratory,hydroposia freely and abrosia for 12 hours before operation.60 rats were randomly distributed into the prior ischemia group(Control group),4h of ischemia group(I group),20 min of reperfusion group(IR20 group),60 min of reperfusion group(IR60 group),120 min of reperfusion group(IR120 group)and 200 min of reperfusion group(IR200 group).The BI-2000 medical analysis system was used to study the change of mesenteric microcirculation at the point of each group.At the same time,blood samples were obtained for measurement of the prostaglandin I2(PGI2),thromboxane A2(TXA2),PGI2/TXA2 in plasma in different groups.Results:⑴Compared with Control group,the I group had no significant difference(P>0.05),the microvascular diameters decreased significantly(P<0.01 or P<0.05)in IR20 group and IR60 group,and increased significantly(P<0.01 or P<0.05)in IR120 group and IR200 group;⑵Compared with Control group,the I group had no significant difference(P>0.05),the blood flow velocity of mesenteric microcirculation decreased significantly in turn(P<0.01)in IR20 group,IR60 group,IR120 group and IR200 group;⑶During the anaphase of reperfusion,the number of rats with significantly adhesive leukocytes and microthrombus increased,even the occurrence of the rupture and hemorrhage of micrangium;⑷The level of PGI2 and TXA2 in plasma dropped after rising while the PGI2/TXA2 decreased(P<0.01 or P<0.05).Conclusion:There are failure of mesenteric microcirculation in rats with IR injury of hind limbs.The above situation may have important relations with the injury of vascular endothelial cells and the unbalance of PGI2/TXA2.