^（14）C－缬氨酸在实验性大鼠肝性脑病脑组织中的示踪观察

(14)C-valine Trace in Brain Tissue of Experiment Rats with Hepatic Encephalopathy

应用放射自显影技术，观察经颈总动脉快速注射示踪剂后大鼠急性肝功能衰竭（ＡＨＦ）所致肝性脑病（ＨＥ）的脑组织对（１４）Ｃ－缬氨酸的摄取情况，并电镜观察其血脑屏障（ＢＢＢ）改变。结果发现，ＨＥ大鼠脑组织对（１４）Ｃ－缬氨酸的摄入量较正常大鼠增多（ｐ＜０．０５）。电镜下可见神经胶质细胞和毛细血管内皮细胞胞浆中囊泡增多．说明大鼠８Ｂ８对（１４）Ｃ－缬湖氨酸的通透性增加。实验性ＨＥ大鼠ＢＢＢ结构和功能均有改变。本研究提示：临床上经静脉输入高浓度支链氨基酸（ＢＣＡＡ）治疗ＡＨＦ引起的ＨＥ可以促使脑组织ＢＣＡＡ浓度增加。

ranch-chain aminoacid is often given through intravenation or oral administration in the clinicaltreatment of hepatic encephalopathy due to acute hepatic failure. We observed the uptake of(14)C-valinein brain tissue of rats with hepatic encephalopathy due to acute hepatic failure,Autoradiography tech-nique was used after rapid injection of the drug into the rat common carotid artery.We observed thechanges of blood-brain barrier with electron microscope;The results showed that the uptake of(14)C-va-line in brain tessue of rats with hepatic encephalopathy was more than that of the control.Under elec-tron microscope astroglia and capillary endothelial cell showed increased vesicles. Our results indicatedthe permeability of(14)C-valine was increased in blood-brain barrier of rats with hepatic encephalopathy. Both the structure and function of blood-brain barrier in rats with hepatic encephalopathy had changed.Our study suggested that in the treatment of hepatic encepalopathy due to acute hepatic failure intrave-nation of branch-chain aminoacid of high concentration might increase the concentration of branch-chainaminoacid in brain tissue.