异氟烷预处理对大鼠肝缺血再灌注时脑线粒体钙及线粒体转运通道的影响

目的：通过观察在体大鼠肝部分缺血再灌注损伤后脑线粒体游离钙、线粒体转运通道（ mitochondrial permeability transition pore ，MPTP）及外周血中S-100β蛋白含量的变化，明确异氟烷预处理对大鼠肝部分缺血再灌注时脑损伤是否具有保护作用及可能的机制。方法 SD大鼠75只随机分成假手术组（ S组）；缺血再灌注组（ I/R组）：肝缺血60 min，再灌注120 min；异氟烷预处理组（ ISO组）：肝I/R前60 min ISO预处理30 min，后用空气洗脱30 min：CsA＋ISO组，CsA50 mg/kg静脉内注射，30 min后同ISO组；CsA组，I/R前30 min CsA50 mg/kg静脉内注射。再灌注24 h迅速断头取前脑，分离线粒体进行线粒体游离钙、MPTP含量检测，各组分别于缺血前及再灌注120 min后抽取静脉血采用双抗体夹心-ELAISA 法测定 S-100β蛋白含量。结果 I/R组（287.32±26.17）线粒体游离Ca2＋浓度明显增加，高于S组（198.54±21.02）和ISO组（209.74±29.49）（P ＜0.05）；CsA＋ISO（267.31±37.52）明显高于ISO组（ P ＜0.05）；CsA（288.63±23.15）组与I/R组间比较差异无显著意义（ P ＜0.05）；I/R组（1.73±0.24）的ΔS与S组（2.36±0.35）和ISO 组（2.11±0.32）相比明显减少（P ＜0.05），既MPTP大量开放，而后两组的差异无统计学意义（P ＜0.05）；I/R组与CsA＋ISO组（1.72±0.34）和CsA组（1.77±0.35）△S之间差异无统计学意义（P ＜0.05）；CsA＋ISO组的ΔS值与ISO组相比明显降低（P ＜0.05）。外周血液S-100β蛋白I/R组明显高于S组和ISO组（P ＜0.05）；CsA＋ISO组与ISO组比较显著升高（P ＜0.05），I/R组，CsA＋ISO组和CsA组与缺血前比较明显升高（ P ＜0.05），缺血前S-100β蛋白含量五组无显著性差异（ P ＜0.05）。结论大鼠肝部分缺血再灌注后对脑组织造成了一定程度损伤，而异氟烷预处理对此损伤具有一定保护作用；其作用的机制可能与异氟烷抑制MPTP开放，降低线粒体游离Ca2＋浓度，防止了线粒体Ca2＋超载有关。

Preconditioning effect of isoflurane on mitochondria free calcium concentrate and mitochondria permeability transition pore after liver ischemia-reperfusion injury in rat brain

Objective To investigate the protective effect and the mechanism of isoflurane preconditioning on rat brain tissue suffering from rat liver ischemia-reperfusion injury .Methods 75 SD rats were randomly divided into five groups, sham group （S group）;ischemia-reperfusion group （I/R group）： liver ischemia for 60 min, reperfusion for 120＆amp;nbsp;min;isoflurane preconditioning group （ ISO group ）： 60 min before liver I/R, ISO pretreatment for 30 min; CsA ＋ISO group;CsA （ MPTP specific blocker ） 50 mg/kg intravenous injection , the same as ISO group after 30 min; CsA group：CsA 50 mg/kg intravenous injection .30 min before I/R.The animals were killed 24 h after ischemia and their brain were excised for measurement of mitochondrial permeability transition pore （ MPTP） and calcium content in mitochondria .The measurement of content of S-100βprotein in serum before ischemia and 120min after reperfusion through the application of Elisa kit.Results The mitochondrial Ca2＋concentration of I/R group（287.32 ±26.17）was higher than that in S group （198.54 ±21.02） and the ISO group （209.74 ±29.49） （ P 〈0.05）, and Ca2 ＋ concentration of CsA ＋ISO group （267.31 ±37.52） was higher than the ISO group （P 〈0.05）;there was not statistical significance between I/R and CsA group（288.63 ±23.15）（P 〈0.05）.MPTP were more opened in I/R group（△S：1.73 ±0.24）than that in S group （△S：2.36 ±0.35）and ISO group（△S：2.11 ±0.32）（P 〈0.05）,but MPTP were more opened in CsA ＋ISO group than that in ISO group （P 〈0.05）.The content of S-100βprotein in serum was significantly higher in I/R group than that in sham and ISO groups （P 〈0.05）,and the content of S-100βprotein in serum was significantly higher in CsA ＋ISO group than in the ISO groups （ P 〈0.05 ） .Conclusion The liver ischemia-reperfusion may injury the brain of the rat and isoflurane preconditioning can protect the brain on the rat .The reduce of mitochondria calcium overload and inhibition of MPTP opening are involved in the mechanism .