他克莫司对脂肪肝供体大鼠肝移植围手术期移植物功能保护作用的研究

Protection of fatty liver grafts with tacrolimus after rat orthotopic liver transplantation

目的探讨他克莫司对脂肪肝供体大鼠肝移植围手术期移植物功能的保护作用及机制。方法建立脂肪肝供体Wistar大鼠肝移植模型,实验组与对照组受体大鼠分别在术中、术后注射他克莫司(0.3mg/kg)或生理盐水,在移植物再灌注0h、24h、72h和1周后分别检测两组受体大鼠的血清肝酶[丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、乳酸脱氢酶(LDH)]、内皮素(ET)和脂质过氧化指标[超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)],同时取肝组织制成匀浆检测其SOD、CAT和MDA水平,取小块肝组织制成切片在电镜下观察肝脏超微结构,采用原位末端标志法(TUNEL)检测肝组织的细胞凋亡情况。结果实验组大鼠的血清ALT、AST、LDH、ET和MDA水平明显低于对照组,SOD和CAT高于对照组(P<0.05),实验组大鼠的肝组织匀浆中MDA水平也显著低于对照组,SOD和CAT高于对照组(P<0.05)。实验组肝脏超微结构的损伤程度和细胞凋亡程度均较对照组有所减轻。结论他克莫司能在一定程度上保护脂肪肝供体大鼠肝移植围手术期移植物的功能,其作用机制可能与其抑制脂质过氧化、细胞凋亡和减轻再灌注损伤有关。

Objective To study the protective role and possible mechanism of tacrolimus on the graft function after rat orthotopic liver transplantation with fatty liver graft.Methods Orthotopic liver transplantation transplanted with fatty liver grafts in Wistar rats were established.Rats in experimental group were treated with tacrolimus （0.3 mg /kg） while control group with normal saline during and post transplantation.The serum levels of hepatic enzymes （ALT,AST,LDH）,ET,and lipid peroxidation index （SOD,CAT,MDA） were tested at 0 hour,24 hour,72 hour and 1 week after liver transplantation,and lipid peroxidation index was also measured in liver tissue homogenate at the same time point in these two groups.Ultramicroscopic morphological changes of liver tissue were checked under electron microscope,and cellular apoptosis of liver were detected using TUNEL method.Results The serum levels of ALT,AST,LDH,ET and MDA in experimental group were significantly lower than those in control group （P 0.05）,while SOD and CAT levels were higher compared with the latter （P 0.05）.The tissue homogenate level of SOD in experimental group was also reduced when compared with the control group （P 0.05）,while SOD and CAT levels were higher than those in the control group （P 0.05）.The ultramicroscopic morphological demonstrated less severe damage of liver tissue and the TUNEL assay showed less cellular apoptosis in experimental group compared with the control group.Conclusions Tacrolimus may protect graft function in rat orthotopic liver transplantation with fatty liver donor to a certain extent.The possible mechanism of tacrolimus protection may be achieved by inhibiting lipid peroxidation,lessening cellular apoptosis and alleviating reperfusion injury.