Establishing an animal model for the post-injury regenerating ability of rats exposed to the repeated +Gz forces

Objective: To analysis the Post-injury Regenerating Ability of rats exposed to the repeated +Gz forces,A animal model was established.Methods: A hundred and eight male rats were randomly assigned to 9 groups with 12 rats in each group.Group A was normally fed as the blank control group.Group B was only fixed with rat-kept devices for 5 minutes as the fixed control group.Group C was borne +1Gz for 5 minutes.In the same position as group C,group D,E,F,G,H and I were repeatedly exposed to +10Gz for 30 seconds each time with 5 times a day and +1Gz for 1 minutes as a interval;the 6 groups were treated in the condition above for 4 days a week and 4 weeks in total.The rats in group A,B,C and D were killed on the next day after the centrifuge.The others in group E,F,G,H and I were killed at the week 1, 2,4,8 and 12 after the centrifuge,respectively.After the rats were killed,temporomandibular joint,masticatory muscles,heart,liver and kidney were taken for（observe） under optical microscope,scanning electron-microscope（SEM） and transmission electron-microscope（TEM）.（Results: All） rats survived before killed.There was no significant difference observed in every organ and tissue in group A,B and C.Heart,liver,temporomandibular joint and masticatory muscles showed pathological changes to different extent in the other groups,except kidney.As time going,the above injury weakened and regenerated gradually.Conclusion: The animal model,which has good repetition,is a perfect model to study the Post-injury Regenerating Ability of rats exposed to the repeated +Gz forces.It was confirmed that the repeated +Gz could induce the injury of temporomandibular joint,masticatory muscles,heart and liver,which could be self-regenerated in different period after.