兔实验性肝性脑病1H磁共振波谱初步研究

目的:研究兔实验性肝性脑病1H磁共振波谱(magnetic resonance spectroscopy,MRS)变化。方法:将24只兔子随机分三组:对照组,肝硬化组,肝性脑病组,各8只。肝性脑病组采用四氯化碳(CCl4)联合内毒素方法制作肝性脑病兔子模型,肝硬化组采用CCl4制作肝硬化模型。分别在第4、6、8、10、12周取肝脏病理活检,第12周测量血氨值,并进行兔子脑组织的MRS扫描。计算N-乙酰天门冬氨酸(N-acetyl asparte,NAA)、肌酸(creatine,Cr)、胆碱(choline,Cho)、肌醇(myo-inositol,mI)和谷氨酰胺复合物(glutamine and glutamate,Glx)的峰下面积,计算NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr。结果:与对照组及肝硬化组相比,肝性脑病组兔血氨上升,脑部MRS显示Glx/Cr升高,Cho/Cr降低,差异显著(P0.05)。与对照组相比,肝硬化组血氨以及MRS改变无统计学意义。结论:兔实验性肝性脑病1H磁共振波谱存在变化。

Preliminary Study of 1H-Magnetic Resonance Spectroscopy in Rabbit Model of Hepatic Encephalopathy

Objective:To investigate the change of brain MRS in rabbits model of hepatic encephalopathy.Methods:24 experimental rabbits were randomly divided into three groups: control group, cirrhosis group and hepatic encephalopathy group, with 8 rabbits in each group (n=8). In hepatic encephalopathy group CCl4 combining with endotoxin were used to produce the rabbit model of hepatic encephalopathy, whereas CCl4 was used to get the rabbit model of hepatic cirrhosis in cirrhosis group. Pathological changes of rabbit livers of cirrhosis group and hepatic encephalopathy group were pathologically confirmed by liver biopsy under the ultrasonic guidance in the fourth, sixth, eighth, tenth, and twelfth week separately. The values of blood ammonia were measured in the twelfth week and meanwhile the magnetic resonance spectroscopy scans of rabbit brains were performed by using stimulated echo acquisition mode spectroscopy sequences.Then area under peaks of each metabolite, including NAA, Cr, Cho, mI, Glx and their ratios to Cr (NAA/Cr, Cho/Cr, mI/Cr, Glx/Cr) were computed and compared with the control group.Results:Comparing the control group with the cirrhosis group, the blood ammonia values of rabbits raised in hepatic encephalopathy group, meantime the brain MRS results of rabbits showed significantly increased Glx/Cr and significantly decreased Cho/Cr (P<0.05).Conclusion:Compared with control group and cirrhosis group, there exist changes in the brain MRS results in rabbits of hepatic encephalopathy group.