将６０％的四氯化碳油皮下注射建立大鼠肝硬变模型时，日龄大小差异对成功率有显著影响。日龄小的大鼠死亡率高；日龄大的死亡率低，成功率可高达７０％以上。这表明日龄小的大鼠免疫机能建立不完善，耐受性差，不适于做模型。同时证明日龄过大（１２月以上）的大鼠不如１８０日龄的大鼠 Subcutaneous injection of 60% carbon tetrachloride oil to establish rat cirrhotic model, the difference in day-old size has a significant impact on the success rate. Day-old rats with high mortality rate; high mortality rate of day-old, the success rate can be as high as 70%. This shows that the age of rats immune function imperfectly established, poor tolerance, not suitable for the model. At the same time, it was proved that rats older than age (above 12 months) were not as good as those of 180 days old rats