脑死亡状态下巴马小型猪肝脏功能和形态的变化

目的:观察脑死亡状态下肝脏功能和形态的变化.方法:巴马小型猪10只,随机等分为脑死亡组和对照组.脑死亡组应用改进的缓慢间断颅内加压法建立脑死亡模型,通过呼吸、循环支持维持脑死亡状态24 h;对照组维持麻醉24 h,不建立脑死亡模型.分别测定脑死亡后3 h、6 h、12 h、18 h和24 h各组动物血清中ALT、AST水平,并与对照组相应时点比较.观察各时点肝脏组织学变化及超微结构变化.结果:脑死亡组12 h、18 h、24 h血清ALT、AST水平均高于对照组相应时点和脑死亡组前一时点(P均＜0.05).脑死亡组12 h可见肝细胞轻度浊肿,胞浆疏松化,12 h电镜发现肝细胞内出现轻微线粒体肿胀,24 h可见线粒体肿胀,嵴消失,甚至线粒体部分膜溶解、内质网扩张呈池状等改变.对照组光镜及电镜下未见明显的损伤性变化.结论:脑死亡状态导致肝脏出现功能和形态的损伤性变化,随着脑死亡维持时间的延长而加重.

Changes of hepatic morphology and function in brain-dead Ba-Ma mini pigs

Aim: To investigate the changes of hepatic function and morphology in the brain-dead state. Methods: A total of 10 Ba-Ma mini pigs were randomized into 2 groups: brain-dead group and control group. Brain-dead model was established by increasing intracranial pressure in a modified, slow and intermittent way, and maintained brain-dead state for 24 h by respiration and circulation support. The serum ALT, AST levels were determined. The alterations of hepatic tissue and the ultrastructure of hepatic tissue were observed. Results: Compared with control group and the former time point of brain-dead group,levels of serum ALT and AST in brain-dead group at 12 h,18 h,and 24 h were higher (P<0.05). Under light microscope, within 12 h after the initial brain-death, slight hepatic cell edema and hepatic cell sparsity could be observed. Under electron microscope, at 12 h, mitochondrion mildly swelled,and at 24 h, cytoplasm edema, mitochondrion swelling, crista disappearance, membrane dissolution of mitochondrion, endoplasmic reticulum dilation were observed,and no obvious morphological injury was observed under light microscope and electron microscope in control group. Conclusion: Brain death may evoke hepatic functional and morphological injury,which aggravates with the prolongation of brain-dead state.