Objective: To observe the different degrees of nontraumatic brain injury side (Contralateral brain tissue, CBT) changes in brain edema and the therapeutic effect of AQP4-siRNA application, while the feasibility of monitoring the CBT area ADC value edema change.
Methods: Healthy March age 198 rats, according randomly divided into sham group (n=18), fell injury group (n=90) and AQP4-siRNA treatment group (n=90), using controlled cortical impactor (controlled cortical impact, CCI) prepared mild and severe trauma rats with brain contusion and treatment groups after contusion press time 1 h, 24 h, 48 h, 72 h, 168 h each divided into five sub-group (n=18), each group were sacrificed at the above time and randomly selected three death row before MR imaging followed by pathological changes in electron microscopy CBT edema and BBB (blood-brain barrier, BBB) blood-brain barrier (blood-brain barrier, BBB) integrity (n=2), and Western blot AQP4 expression (n=6), brain water content measured (n=10), analysis of changes of CBT brain injury edema, AQP4-siRNA interference treatment and MRI features.
Results: AQP4 expression of mild group CBT, ADC value and pathological changes in 1 h, 24 h and 48 h normal, 72 h after AQP4 appears the slightly reduced after 7d appears significantly higher, ADC value 72 h appears significantly reduced, then increased 7d pathological 72 h CBT display area of the cells within the current mild edema, 7d appear mild hybrid edema; prophylactic treatment after AQP4-siRNA AQP4 in 48 h, 7d group showed significantly lower than the trauma (P<0.05), ADC display 48 h somewhat lower than the trauma group, 72 h significantly increased, 7d significantly lower (P<0.05), showed that the treatment group compared with the pathological trauma group at 72 h and 7d relieve cerebral edema. AQP4 expression of severe injury group CBT region 1 h is significantly higher than the control group, 24 h, 48 h, 72 h sustained decline, then to 7d recovery, AQP4-siRNA treatment after 24 h to 72 h CBT of AQP4 in significantly lower (P<0.05), pathology showed severe injury group CBT area in the early (1 h) that is out now vasogenic edema, 24 h to 48 h in the main intracellular edema, 72 h to 7d was mixed edema; treatment group within 24 h to 48 h cell edema improve, 7d hybrid significantly reduced edema, severe trauma group CBT area ADC value in the early (1 h) that is significantly higher in 24 h to 48 h reduction, early treatment group ADC value (1 h) no significant difference between the trauma group, 24 h significantly higher than the bruise.
Conclusion:Severe contusion and mild contusion after CBT area was now different pathological changes in edema after severe brain contusion early CBT region appears vasogenic edema, which subsequently led to brain tissue edema and mixed edema, AQP4-siRNA cannot early mitigation vasogenic brain edema, but may then occur within AQP4 expression by reducing brain edema and mild reduction of cell hybrid edema. Mild group CBT area in the late (72 h) appears cytotoxic edema, AQP4- siRNA can alleviate cerebral edema. ADC value change of AQP4 expression and edema have a certain type of contact that can provide valuable information for the image after TBI diagnosis and treatment of cerebral edema judgment. It can be used as a means to assess the body image depending on the degree of injury at different time periods to observe changes in brain edema and treatment CBT area.