Expression Of OX-42and EP2in The Hippocampus Of Rat Brain After Pure Cerebral Concussion And The Effect Of The Intervention With AH6809

Objective:This study aimed to investigate the expression changes of the microglia (MG) in hippocampus after the pure cerebral concussion (PCC) and to explore whether microglia are involved in the pathological changes and changing characteristics after brain injury.Methods:Under the waking state, rat models of PCC were created by using a metallic pendulum-striker concussive device. The rats were randomly divided into PCC3h,12h,1d,2d,3d and7d (n=5for each time point) groups after injury. One control (normal) group (n=5) was used. To observe the distribution and immuno-expression changes of OX-42in hippocampal areas including CA1～4and dentate gyrus between the PCC group and the control group, the immuno-histochemical staining (SP) and immunofluorescence staining were used with OX-42monoclonal antibody (special marker labed with MG).Results:The results showed that OX-42immunoreactivity was rarely, even hardly, observed the expression of OX-42appeared to increase gradually in the CA1-4of hippocampal area and dentate gyrus after brain injury when compared with the control, and showed a downward but still higher than the control after7d.Conclusion:The results that MG were activated with the changes in morphology and quantity in the hippocampus during the early stages of injury suggest that MG may be involved in pathological changes after the PCC. Objective:To investigate the expression changes of the EP2in hippocampus after the pure cerebral concussion (PCC) and the pathological changes of EP2immunoreactive expression. Moreover, the role of AH6809intervention in EP2expression was examined.Methods:Under the waking state, rat models of PCC were prepared by using a metallic pendulum-striker concussive device. The rats were randomized into PCC3h,12h,1d,2d,3d and7d (n=5for each time point) groups after injury. One normal group (n=5) was used as control. The groups of intervention with AH6809were randomly divided into1d,2d,3d and7d (n=5for each time point) groups. One control (PCC+NaCl) group (n=5) was set up. To observe the distribution and immuno-expression changes of EP2in hippocampal areas including CA1～4and dentate gyms after PCC, and the role of the intervention AH6809in the EP2expression, the immune-histochemical (IHC) staining (S-P method), Western Blotting and RT-PCR were used respectively.Results:Results of SP staining, WB and RT-PCR revealed that the expression of EP2exhibited increasing gradually in the hippocampus after PCC when compared with the control, and its expression level showed the most highest in the3d group (p<0.05). It has been demonstrated that EP2expression have a trend of gradually decline after intervention of AH6809by IHC, WB and RT-PCR.Conclusion:The results that EP2receptor with the regular changes in the hippocampus after PCC suggest that EP2receptor are involved in pathological changes after the PCC, and the AH6809have effective inhibitory role in EP2expression. Objective:To investigate the morphological changes of neurons at different regions of hippocampus in rats after PCC and the pathological connections between neurons and traumatic brain injury. Moreover, the role of AH6809intervention in the neuronal changes was examined.Methods:Under the waking state, rat models of PCC were prepared by using a metallic pendulum-striker concussive device. The rats were randomly divided into PCC3h,12h, Id,2d,3d and7d (n=5for each time point) groups after injury. One normal group (n=5) was set up as control. The groups of AH6809intervention were randomly divided into1d,2d,3d and7d(n=5for each time point)groups. One control(PCC+NaCl) group (n=5) was set up in order to observe the morphological changes of the neurons in hippocampus and the role of AH6809intervention in neuronal changed with Nissl staining.Results:Results showed that some pyknosis and necrotic cells appeared in the hippocampus and increased over time in the1d,2d,3d after PCC when compared with the control, and the pyknosis and necrosis of cells was the most prominent in the3d group (p<0.05). The number of the pyknosis and necrosis neurons appeared a obvious trend of decline after AH6809intervention(p<0.05)Conclusion:Morphological changes of neurons in hippocampus after PCC suggest that brain injury would result in the pyknosis and necrosis neurons in hippocampus. With the intervention of AH6809, the number of pyknosis and necrosis neurons appeared decrease in hippocampus occurred.