脑死亡状态下细胞色素B5在供肝的表达及意义

The effect of cytochrome B5 on hepacyte under brain death

目的观察细胞色素B5在脑死亡时对肝细胞的损伤作用。方法将10只新西兰兔随机分为对照组及脑死亡8h组（n=5），对照组维持麻醉8h，脑死亡组采用渐进式颅内加压模型建立脑死亡动物模型，维持脑死亡8h，分别取肝脏标本采用原位缺口末端标记法（TUNEL）、Western blot、反转录一聚合酶链反应（RT—PCR）的方法检测细胞凋亡、细胞色素B5和细胞色素C的表达。结果脑死亡组相对于正常组，肝脏组织细胞凋亡率明显增加，差异有统计学意义[（82±2）％比（10±2）％，P〈0．05]。同时脑死亡组肝脏组织细胞色素B5的表达水平下降[（70±2）％比100％，P〈0．05]，细胞色素C表达上升[（130±3）％比100％，P〈0．05]，差异有统计学意义。结论细胞色素B5可能在脑死亡后肝脏损伤过程中起保护作用。

Objective To investigate the effect of cytochrome B5 on hepacyte under brain death. Methods A total of 10 New Zealand rabbits were divided into control group and brain death 8 h group （n = 5）, in both group a Fogarty 3F catheter was placed in intracalvarium. Brain death model was established by increasing intracranial pressure in a modified and intermittent way, while control group was just keeping anesthesia for 8 h. After 8 h of brain death liver samples was harvested. Western blotting, reverse transcription -polymerase chain reaction and co -immunoprecipitation were employed on livers samples of both group to detect the expression of cytochrome C and cytochrome BS. Results The expression of cytochrome B5 in brain death models decreased significantly [ （70 ±2）% vs. 100%, P 〈0. 05] while expression of cytochrome C increased significantly [ （ 130 ± 3） % vs. 100%, P 〈 0.05 ], compared with control. Meanwhile, the apoptosis rate of brain death model was significantly higher than control [ （ 82 ± 2 ） % vs. （ 10 ±2） % , P 〈 0. 05 ]. Conclusion Cytochrome B5 may have a protective effect against brain death induced live cells apoptosis.