Research On The Viral Myocarditis Mice Model Of Enterovirus 71 Infection And Therapeutic Effect Of Using 3-azole Nitrogen Nucleoside

Objective To establish the viral myocarditis mouse model of enterovirus 71(EV71) infected, and to observe the clinical manifestations of 1-day-old BALB/c mice infected with EV71. At the same time, 3-azole nitrogen nucleoside was used to treat the model. then, we observed the clinical changes, measured the level of serum marker, watched the myocardial pathology and assessed the clinical application value of the drug.Methods The study involved in vivo experiments, and it was divided into two parts: 1. Determined the appropriate dose of virus infection: Firstly, forty 1-day-old BALB /c suckling mice(4 nests) were randomly selected and divided into four groups, 10 /each. Selected one group from the four groups randomly as the control group, and they were injected with culture suspension of Vero cells through intraperitoneal(IP), 0.1ml/each, and the remaining three groups were injected with different concentrations of EV71 virus solution,0.1ml/each. Then we observed the clinical changes, measured the level of creatine kinase isoenzymes(CK-MB), watched the myocardial pathology and determined the appropriate dose of virus infection. 2. Treated the model with 3-azole nitrogen nucleoside and assessed the efficacy of the drug: 60 BALB/c mice were randomly selected and divided into six groups.Two groups were selected as the normal control group and 3-azole nitrogen nucleoside control group, and they were injected suspension of Vero cell, 0.1ml/each. The remaining four groups were injected with 104 TCID50 dose of EV71 through intraperitoneal(IP), 0.1ml / each, and they were divided into four groups gain. Each dose group was given respectively 100 mg/kg, 10 mg/kg,1mg/kg of 3-azole nitrogen nucleoside by intraperitoneal injection. After sacrifice, the serum and heart tissue of each mouse were collected. The heart tissue was used for virus isolation, reverse transcription-polymerase chain reaction(RT-PCR) and pathologic examination. The changes of creatine kinase isoenzymes(CK-MB) in serum were determined.Results 1.Infected mice appeared varying clinical symptoms:2~3 days appeared the poor spirit, irritability, and poor activity, 4~5 days appeared drowsiness, paralysis of hind limb and ataxia, 5~7 days appeared death. The models successfully were proved with virus isolation from heart tissue, the results of RT-PCR, the changes of histopathology and the high level of CK-MB. And the experiments show that 104 TCID50 was appropriate infectious dose. 2. Compared with the model group, the clinical manifestation of 3-azole nitrogen nucleoside each dose group was alleviated, and the level of CK-MB and mortality were obviously reduced. There are significant differences(all P<0.05), especially the high dose of 3-azole nitrogen nucleoside group. In addition, the pathological changes of 3- ribavirin treatment groups of mice myocarditis and necrosis were significantly lighter than the model group, and the high dose group changed less inflammatory than the low dose group.Conclusions The mouse could be infected with EV71 AH12206 strain and lead to vital myocarditis, the model can be used to study the pathogenesis of viral myocarditis and to assess the effect of antiviral drugs. 3-azole nitrogen nucleoside could improve the clinical symptoms; reduce the mortality, and alleviate the damage in the heart tissue. It has some contribute to cure vital myocarditis.