Study On Expression And Different Expression Of GFAP,CHOP And Caspase-12 In Prefrontal At Mechanical Injury Areas Of Rat

Objective: To investigate methods to infer Injury Time of brain; Assess to the value of the cytokines generated in the process of tissue repair and endoplasmic reticulum stress in inferring;Comparison the significance of several cytokines in early and late brain injury in inferring the injury time.Methods: Using forebrain locator locate 4.6mm before the anterior fontanelle and left 2mm,zone of M2,according to the brain atlas, needle puncture depth of 2mm, making frontal damage modeling,as to the model control group, the corresponding parts of the drilling only, without needle, Respectively, after the injury time of 2h, 6h, 12 h, 24 h, 3d, 7d and 14 d, sacrificing the rats in brain injury. Remove the damage tissue of brain, puting it in 10% neutral formalin fixed 24 h, dehydration in the different concentrations alcohol, dipping wax,embedding with wax and madeing Pathological film at last,to make the GFAP, CHOP and Caspase-12 expression in damage tissue of brain by immunohistochemical staining technique, analysising the value of IOD(average light gray) and AOD(mean optical density) of GFAP, CHOP and Caspase-12 in various periods of time, Lesion formation time to do correlation analysis, discriminant the value of three indicators inferring injury time in early and late injury brain between the formation and the time based on the return of the three indicators.Results: Analysis experimental data with spss software conclued charts and scatter plots display: ①GFAP index group, the IOD and AOD values of control group and different time damage groups pairwise comparisons show P <0.05, 2h and 6h group, 3d and 14 d group P> 0.05 in IOD values group,but P> 0.05 between 6 and 12 h group in AOD values, IOD and AOD values continue to increase in GFAP at 2h-7d group, and peaked between 7d to 14 d group, 14 d group began to close down a similar trend throughout the expression curve like bell. IOD of GFAP at each injury time linear regression of secondary fitting R2 = 0.956, regression equation Y = 1.997X2 +870.192 X +58318.828, AOD values of quadratic regression fitting R2 = 893, the regression equation Y =-7.595 × 10-6X2 +0.03 X +0.213.② CHOP index group, IOD values of the control group and group of 2h-7d pairwise comparison shows P <0.05, between the control group and 14 d group P > 0.05, AOD values between 3d and 7d group P> 0.05, between the control group and the rest of the groups P <0.05, at IOD index,the expression of CHOP reducethe with extension of injurie time,but 2h group and 6h group decreased obviously, 6h to 24 h group decline slowed, The middle of regression curve have a "platform",3-14 d group expression continued to decline, to 14 d,the expression abundance of CHOP have a approaching trends to the control group. the IOD of CHOP at different injury time linear regression of relevance R = 0.529, regression equation was Y =-133.269 x +44009.463, AOD values shown a downward trend similar to IOD, the degree of correlation R = 0.642, regression equation was Y =-0.122 X +40.331.③ Caspase-12 index group, between the control group and the model group at each time AOD values P 0.05, control group and injury group IOD value <0.05, Caspase- 12 expression in a transient increase in 6H groups. With injury time after a prolonged rapid decline over three groups to 14 d group, decreased expression gentle, linear regression is not obvious. between the control group and the model group of different injury time in AOD values P <0.05, between 24 h and 3d group in IOD values P > 0.05, Between the control group and the injury group in IOD values P <0.05, Caspase-12 expression in a transient increase at the 6h group and with the extension of the injury time rapid decline, three days set to 14 d group, decreased gentle, the linear regression is not obvious.Conclusion: the relationship between the expression of GFAP and damage elapsed time have a regression curve,and has a obvious peak, which providing an effective way and mean to infer the injury formation time of brain;CHOP protein occurs high levels of expression at around 2h after brain injury, the trends of CHOP close to the control level after 3d when injury, the trend change quickly, which provide a certain value to infer the formation time of the early brain injury; peaking of Caspase-12 in brain damage occurs around 6h after injury, and close to the control level after 24 h of injury, that providing some references for estimation of the formation time in early brain injury.