不同滴度轮状病毒对新生小鼠肝胆系统损伤的比较

Comparison of hepatobiliary injury for newborn BALB/c mice which induced by different titers of rhesus rotavirus

目的 比较不同滴度轮状病毒（Rhesus rotavirus,RRV）对新生小鼠肝胆系统损伤的差异.方法 新生小鼠出生24 h内,腹腔注射恒河猴轮状病毒（MMU18006病毒株）建立肝胆损伤动物模型;将80只BALB/c新生小鼠随机分成4组,每组20只,实验组分别注射不同滴度轮状病毒悬液,依次为高滴度（1×107 PFU/ml）、中滴度（1×10^6 PFU/ml）、低滴度实验组（2.5×10^5 PFU/ml）,正常对照组仅注射病毒培养液;观察小鼠体重、黄疸发生时间,于出生后第12天收取标本时,经小鼠胆囊行肝外胆道造影,镜下观察小鼠胆管情况,并收取血清和肝胆组织,分别进行肝功能检测和病理染色分析.结果 与正常小鼠相比,实验组小鼠均有不同程度的皮肤黄疸、体重增加缓慢、生存率下降、肝功能损伤.低滴度组表现较轻且皮肤黄疸、体重及肝功能可恢复正常;与低滴度组相比,高滴度组皮肤黄疸更明显,体重显著性降低且不可逆,生存率低（50％）,肝功能指标TBIL、DBIL、TBA、ALT、ALP显著性升高.进一步胆道造影显示高滴度组闭锁率高（80％）,低滴度组无闭锁.病理学分析显示高滴度组肝内胆管闭锁,汇管区大量炎症细胞浸润,而低滴度组肝内胆管形态正常,汇管区仅有少量炎症细胞浸润.结论 不同滴度轮状病毒对新生小鼠肝胆系统影响不同：高滴度易引起胆道闭锁,低滴度引起肝炎.

Objective To compare the hepatobiliary injury difference of newborn BALB/c mice infected by different titers of rhesus rotavirus （RRV）.Methods Neonatal mice （n =80） were randomly separated into 4 groups and were intraperitoneally inoculated with different titers of rotavirus：High titer group （1 × 107 PFU/ml）;Medium titer group（1 × 10^6 PFU/ml）;Low titer group（2.5 × 10^5 PFU/ml）;Control group （only culture medium） within the first 24 hours after birth.All mice were sacrificed at day 12 after RRV inoculation then the liver and blood samples were collected.Meanwhile,mice were observed daily for at least 12 days,including their weight,skin color and survival situation.Liver functions were examined by serum biochemical test and morphologic changes in the biliary tract were observed.Tissue sections underwent H＆amp;E staining and immunohistochemically analysis for the presence of CK19.Results Compared with the normal mice,the mice in the experimental group had different degrees of skin jaundice,weight lost,survival rate decreased,liver function damage.In the experimental group,the symptom of low titer group was light,and could be restored to normal,however,when compared with the low titer group,the mice in the high titer group were serious,their skin jaundice was more obvious,weight was significantly reduced and irreversible,survival rate was lower（50%）,liver function of TBIL,DBIL,TBA,ALT,ALP were significantly increased.Further analysis showed that the high titer group had high bile duct obstruction rate （80%）,with no case of obstruction in the low titer group.Histologic analysis also showed intrahepatic bile duct atresia in the high titer group,a large number of inflammatory cell infiltrated around the portal area,while the morphology of intrahepatic bile duct was almost normal and just a small amount of inflammatory cell infiltrated around the portal area in the low titer group.Conclusions Different titers of rotavirus had different effects on the newborn mice hepatobiliary system：high titer was easy to cause biliary atresia,and low titer caused hepatitis.