Abstract: Background   There are many methods to establish the animal model of liver fibrosis，and carbon tetrachloride（CCl4）is the most commonly used method．Different ways of administration have a certain influence on the success rate of the model．In this study，subcutaneous injection of pure CCl4 was selected．The aim of this study was to investigate the optimal dose and time interval for the establishment of frabbit models of liver fibrosis．Objective　To explore the optimal mode of administration of CCl4 for the establishment of rabbit models of liver fibrosis．Methods　This study was conducted from April to September in 2015.A total of 46 healthy New Zealand white rabbits were selected and randomly divided into four groups，10 for the G0 group，and 12 for each group of G1，G2 and G3．Rabbits in the G0 group were subcutaneously injected of 0.9% sodium chloride solution with a dose of 0.5 ml/kg，and those in groups G1 and G3 were injected with CCl4 into the subcutaneous tissue of back with a dose of 0.2 ml/kg and 0.5 ml/kg respectively，twice a week，for a period of 16 weeks．For the rabbits in G2 group，they were injected with CCl4 into the subcutaneous tissue of back with the initial dose of 0.3 ml/kg，twice a week，then with the dose of 0.4 ml/kg after three weeks of intervention，and 0.5 ml/kg after five weeks of intervention，which was also the maintenance dose till the end of 16-week intervention．At the 4th，6th，8th，10th，12th，14th week of intervention，one rabbit was randomly selected from each group of G1，G2 and G3 to get sacrificed for their live tissue samples．All the rabbits in groups G1，G2 and G3 and two rabbits in the G0 group were sacrificed at the end of 16-week intervention．If a rabbit died during modeling，the liver tissue sample would be taken for pathological examination at once．Results　The death of rabbits were all happened within three weeks of modeling，and significant differences were found in mortality among the four groups （test statistics=7.004，P=0.048），the mortality of rabbits in group G3 was higher than that in groups G0，G1 and G2 （P<0.001）．At the end of 16-week intervention，there were no significant difference in the rate of successfully modeling between the groups （test statistics=4.747，P=0.165）．Conclusion　A dose-escalation regimen of subcutaneous injection of CCl4 with the initial dose of 0.3 ml/kg，can establish rabbit models of liver fibrosis with low mortality．

Key words: Fibrosis, liver；Carbon tetrachloride；Rabbits；Models, animal

摘要： 背景　肝纤维化动物模型的建立有多种方法，而四氯化碳（CCl4）造模法最常使用，而不同的给药途径对造模成功率也造成一定的影响，本研究选择皮下注射纯CCl4，旨在探讨建立家兔肝纤维化模型的最佳给药剂量及时间间隔。目的　探讨CCl4诱导家兔肝纤维化模型的最佳给药方式。方法　2015年4—9月，选用健康新西兰大白兔46只，随机分为4组，其中G0组10只，G1~G3组各12只。G0组皮下注射0.9%氯化钠溶液0.5 ml/kg，G1~G3组分别以0.2、0.3、0.5 ml/kg的分析纯CCl4背部皮下注射，2次/周，共16周。G2组起始剂量为0.3 ml/kg，3周后增加剂量为0.4 ml/kg，5周后增加剂量为0.5 ml/kg，此后维持剂量在0.5 ml/kg。造模后第4、6、8、10、12、14周，分别从G1~G3组随机选取1只家兔，处死并取肝组织标本。第16周处死G1~G3组家兔及2只G0组家兔，造模期间死亡的家兔立即取肝组织标本进行病理学检查。结果　各组家兔的死亡均发生在造模3周内，各组造模3周内家兔死亡率比较，差异有统计学意义（检验统计量值=7.004，P=0.048）；其中，G3组家兔死亡率高于G0、G1、G2组（P<0.001）。第16周时，G1~G3组造模成功率比较，差异无统计学意义（检验统计量值=4.747，P=0.165）。结论　采用CCl4皮下注射，起始剂量为0.3 ml/kg并剂量递增，可成功建立死亡率低的家兔肝纤维化模型。

关键词: 纤维化, 肝；四氯化碳；兔；模型, 动物