α-硫辛酸对大鼠肝缺血再灌注后缺血型胆道病变防治作用实验研.docVIP

α-硫辛酸对大鼠肝缺血再灌注后缺血型胆道病变防治作用实验研 　【摘要】 目的：探讨大鼠肝缺血再灌注（ischemia-reperfusion, I/R）后缺血型胆道病变的发生机制及α-硫辛酸（alpha-lipoic acid, α-LA）对其的防治作用。方法：成年健康雄性SD大鼠90只，随机分为正常对照组（N组）、I/R组、α-LA处理组（LA组），建立全肝缺血再灌注损伤（ischemia-reperfusion injury, IRI）模型。检测血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、γ-谷氨酰转肽酶（γ-glutamyl transferase，GGT）、总胆红素（total bilirubin, TBIL）水平；电子显微镜观察胆小管变化；FITC-Phalloidin显示胆小管F-actin微丝的分布变化，激光共聚焦显微镜采集图像并定量分析。结果：I/R组血清ALT、AST、GGT和TBIL水平与N组相比明显升高（Plt;0.05），LA组血清ALT、AST、GGT和TBIL水平与I/R组相比明显降低（Plt;0.05）。F-actin荧光变化和电子显微镜超微结构改变相符，I/R各组F-actin荧光染色紊乱、减弱，强度明显低于N组（Plt;0.05）；胆小管微绒毛大量脱落，管腔扩张。LA组病理改变较轻，F-actin荧光染色减弱，但程度较I/R组轻，荧光紊乱不甚明显，平均荧光强度高于I/R组（Plt;0.05）；胆小管微绒毛部分脱落，管腔扩张亦不明显。结论：肝脏I/R可造成胆小管F-actin微丝破坏、微绒毛丧失，导致胆小管收缩减弱，胆汁排泄功能受损，这可能是大鼠肝脏I/ R后缺血型胆道病变发生的主要机制；α-硫辛酸通过清除氧自由基，降低脂质过氧化反应，调节细胞内氧化剂-抗氧化剂的含量，保护胆小管F-actin微丝结构免遭缺血再灌注损伤破坏，进而预防和治疗缺血型胆道病变。 【关键词】 α-硫辛酸·再灌注损伤·缺血型胆道病变·肌动蛋白类 【ABSTRACT】 Objective: To investigate the mechanism of ischemic type biliary lesion after ischemia-reperfusion（I/R）in rat liver and the role of α-lipoic acid in the prevention and treatment. Methods: Ninety Sprague Dawley rats were divided randomly into three groups: normal control （N）, ischemia reperfusion （I/R） and alpha-lipoic acid pretreatment （LA） groups. The model of rat hepatic ischemia-reperfusion was established. The activity of serum ALT、AST、γ-GGT and TBIL were measured. The changes of bile canaliculus were observed by transmission electron microscope. The modification of F-actin microfilaments was quantified using FITC-Phalloidin and analysised by confocal laser scanning microscopy （CLSM）. Results: The ALT、AST、γ-GGT and TBIL levels of the ischemia reperfusion group was significantly increased （Plt;0.05）, while the alpha-lipoic acid pretreatment group was significantly decreased （Plt;0.05） compared with the normal control group. Bile canalicular F-actin was destroyed after reperfusion and this modification of F-actin staining was consistent with the observation by transmission electron microscopy. The staining of F-actin in