奥曲肽对兔肝缺血再灌注损伤后心肌细胞损伤的保护作用

The protective effect of octreotide on myocardial injury after hepatic ischemia-reperfusion injury in rabbit

目的 探讨奥曲肽对兔肝缺血再灌注损伤（HIRI）后心肌细胞的损伤是否具有保护作用.方法 采用Pring＇s兔肝脏再灌注模型,将24只新西兰大白兔按数字表法分3组,每组8只;A组（假手术组）、B组（肝脏缺血再灌注生理盐水组）、C组（奥曲肽预适应组）.3组动物肝门阻断前（T1）,阻断后30 min（T2）,再灌注60 min（T3）,120 min（T4）,240 min（T5）采血,测定血清心肌肌酸激酶同功酶（CK-MB）,乳酸脱氢酶（LDH）,血浆丙二醛（MDA）,超氧化物歧化酶（SOD）.再灌240 min切取心脏组织行MDA、SOD水平监测,同时制作病理切片,电镜观察奥曲肽对HIRI后心肌细胞超微结构的影响.结果 （1）阻断前3组CK-MB、LDH比较差异均无统计学意义（P＞0.05）.从缺血30min开始各时点B组、C组CK-MB、LDH均显著高于A组（P＜0.05）,C组又低于B组（P＜0.05）;LDH、CK-MB的高峰分别120 min、240 min.（2）从缺血30 min开始各时点血浆MDA及SOD水平与再灌注后240 min的心肌MDA及SOD值比较：MDA：与A组比较,B组、C组明显高于A组（P＜0.05）,与B组比较,C组明显低于B组（P＜0.05）;SOD：与A组比较,B组、C组明显低于A组（P＜0.05）,与B组比较,C组明显高于B组（P＜0.05）.（3）C组超微结构较B组明显改善.结论 奥曲肽具有稳定心肌细胞膜,减少氧自由基的释放,能改善肝缺血再灌注损伤后心肌细胞超微结构的损伤,对兔肝脏缺血再灌注损伤后心肌细胞损伤具有保护作用.

Objective To study the protective effect of octreotide on myocardial injury after hepatic ischemia-reperfusion in rabbit. Methods Pringle＇s maneuver rabbit hepatic ischemia-reperfusion model was established. 24 adult New Zealand rabbits were random divided into equal 3 groups： sham operative group （ group A） , ischemia-reperfusion group（ group B） and octreotide preconditioning group （ group C ）. The levels of CK-MB（ MB isoenzyme of creatine kinase） and LDH （ 1actate dehydrogenase）, superoxide dismutase （SOD） and malondialdehyde （MDA） of each group were measured at the time before ischemia （T1） , after ischemia for 30 mins （ T2 ） and after reperfusion for 60 mins （ T3 ）, 120mins （ T4 ）, 240 mins （ T5 ）. The SOD and MDA in myocardial tissue of each group were measured after reperfusion for 240 mins. The changes of ultrastructure in the myocardial cell were observed by transmission electron microscopy after reperfusion for 240 mins. Results There was no significant difference in the levels of CK-MB and LDH in serum of each group before ischemia （ P ＞0. 05）. The CK-MB and LDH of group B and C were higher than that of group A （ P ＜0.05） after ischemia for30 mins. The CK-MB and LDH of group C were lower than that of group B in this period（ P ＜0. 05 ）. The highest time point of LDH and CK-MB were after reperfusion for 120 mins and 240 mins. The contents of MDA in group B and group C were higher than that in group A from after ischemia for 30 mins in plasma and after reperfusion for 240 mins in myocardial tissue （ P ＜ 0. 05 ）,and it in group C were lower than that in group B（ P ＜0.05） .The contents of SOD in group B and group C were lower than that in group A from after ischemia for 30 mins in blood plasma and after reperfusion for 240 mins in myocardial tissue （ P ＜0. 05）, and in group C were higher than that in group B（ P ＜0. 05）.The electromicroscope showed that the pathological change of myocardial ultrastructure of group C was slighter than that of group B. Conclusion Octreotide can stabilize myocardial cell membrane and reduce release of oxygen free radical and significantly relieve the injury of myocardial ultrastructure after hepatic ischemiareperfusion in rabbit. Octreotide preconditioning can relieve myocardial injury after hepatic ischemia-reperfusion in rabbit.