异氟烷预处理对大鼠肝缺血再灌注损伤的线粒体机制探讨

Mitochondrial mechanism of isoflurane preconditioning on rat part liver ischemiareperfusion

目的探讨异氟烷预处理对大鼠肝缺血再灌注损伤的作用及机制。方法健康雄性SD大鼠75只,随机分为5组:假手术组(S组),不阻断肝门血供;缺血再灌注组(I/R组),肝脏缺血60 min,再灌注120 min;异氟烷预处理组(ISO组),ISO预处理30 min;环胞菌素A(CsA)+ISO组,CsA 50 mg/kg腹腔内注射,30 min后同ISO组;CsA组,I/R前30 min CsA 50 mg/kg腹腔内注射。各组大鼠于再灌注2 h后迅速断头处死,摘取肝组织分离线粒体,进行线粒体游离钙、MPTP含量检测。结果线粒体游离Ca2+浓度I/R组明显高于S组和ISO组(P<0.05);而CsA+ISO组明显高于ISO组(P<0.05);CsA组与I/R组间差异无统计学意义。I/R组ΔS值与S组和ISO组相比明显降低,即MPTP开放程度明显增加(P<0.05),I/R组与CsA组和CsA+ISO组ΔS之间比较,差异无统计学意义;与ISO组相比,CsA+ISO组的ΔS值明显降低,即MPTP开放程度明显增加(P<0.05)。结论异氟烷预处理对肝脏缺血再灌注损伤具有一定程度的保护作用,这种作用可能与抑制MPTP开放,防止了线粒体Ca2+超载有关。

Objective To investigate the liver protective effect and the mechanism of isoflurane precondition- ing on the rat liver against ischemia-reperfusion. Methods 75 SD rats were randomly divided into five groups, sham group （S group） ;the only separation of the hepatoduodenal ligament, but did not block the hepatic portal blood supply; ischemia-reperfusion group （I/R group） ：liver ischemia 60 min, reperfusion 120 min;isoflurane preconditioning group （ ISO group） ： 60 rain before liver I/R , ISO pretreatment for 30 min, elution in the air after 30 min ; CsA ＋ ISO group ： CsA （MPTP specific blocker） 50 mg/kg intraperitoneal injection,the same as ISO group after 30 min;CsA group：CsA 50 mg/kg intraperitoneai injection at 30 rain before I/R . The rats were killed at 24 h after ischemia and their livers were excised for measurement of mitochondrial permeability transition pore （MPTP） （ultraviolet spectrophotometer） and calcium content in mitochondria （spectrophoto-fluorometer）. Results The mitochondrial Ca2 ＋ concentration of I/ R group was higher than those of S group and ISO group （ P 〈 0. 05 ） , and Ca2 ＋ concentration of CsA ＋ ISO group was higher than that of ISO group （ P 〈 0. 05 ） ; there was no significant difference between I/R and CsA groups. MPTP were more opened in I/R group than those in S group and ISO group （ P 〈 0. 05 ）, there was no significant difference in I/R, CsA ＋ ISO and CsA groups, but MPTP were more opened in CsA ＋ ISO group than that in ISO group （ P 〈 0. 05 ）. Conclusion Isoflurane preconditioning can protect the liver function against I/R injury. The reduction of mitochondria calcium overload and inhibition of MPTP opening are involved in the mechanism.