| Objective:The aim of this study is to use a improved focal traumatic brain injury model in awake rats by graded impact of epidural and then examining MRS and measuring the concentration of MBP in serum at1,6,12,24,72,and168h after the injury to understanding the changes of biochemical metabolism of brain tissue,and helping us to give our patients a early comprehensive diagnosis, a better treatment and an accurate assessment of prognosis.Methods:76healthy adult Sprague-Dawley rats were randomly se-parated to blank control group(n=4,no operation and no injury),sham ope-ration group(n=24,operation but no injury),mild traumatic brain injury an-imal model group(n=24,500g.cm),severe traumatic brain injury animal m-odel group(n=24,1000g.cm).The animals were examined at1h,6h,24h,72h,and168h posttrauma.Injury groups were divided into6subgroups acco-rding to the six time points(n=4, in each subgroup). Injury groups used a improved focal traumatic brain injury model in awake rats by graded imp-act of epidural and then examined the NAA/Cr and Cho/Cr of cortical ar-eas surrounding contusion lesions in the brain tissue by MRS and measur-ing the concentration of MBP in serum by ELISA. The physiological res-ponses, pathological changes of brain were observed in76rats.Results:1、The ratio of NAA/Cr was significantly lower in mild injury group at1h after injury,about30%reduction compared to control group.The rat-io kept to decrease from6h to24h after injury,and the lowest was24h aft-er injury, about55%reduction compared to control group.The ratio of NAA/Cr started to recovere at72h after injury,and there was a significan-tly recovered at168h after injury, about80%of the ratio of control group. The ratio of NAA/Cr was significantly lower in severe injury group at1h after injury,about37%reduction compared to control group.The ratio ke-pt to decrease from6h after injury to168h after injury.The ratio of NAA/Cr did not recovere at72h and168h after injury, The ratio of NAA/Cr in severe injury group was significantly lower than mild injury group at the points in time of lh,6h,72h,168h after injury(P<0.05). 2、The ratio of Cho/Cr was not significantly higher at lh,6h,and12h after both mild and severe injury than the ratio of control group(P>0.05), while the ratio was significantly higher than the ratio of control group at24h(about31%increase) in mild injury, the ratio was significantly higher than the ratio of control group at24h(about38%increase) in severe injury. The ratio of Cho/Cr recoved little at168h after injury,while there was no significantly different from time of72h after injury.3、The concentration of MBP in mild injury was not significantly hi-gher than blank control group at1h and6h in mild brain injury group,wh-ile there was a significantly increase at12h after injury,and apeak appear-ed at24h after injury.The concentration were significantly higher than co-ntrol group(P<0.05),and it started to recover at72h to168h after injury, while still higher than control group. Way of change with time of the con-centration of MBP in severe injury after injury liked it changing in mild injury,while the increase of the concentration of MBP in sereve injury gr-oup at12h and24h after injury was significantly higher than it in mild in-jury(P<0.05),and decreased more slowly than mild injury the point of ti-me after24h(P<0.05).5、Cho/Cr and MBP had a significant positive correlation by using Pearson correlation analysis in both mild injury and sereve injury. NAA/Cr and Cho/Cr,NAA/Cr and MBP had a negative correlation by using Pearson correlation analysis in sereve injury.Conclusions:1、Our study shows the ratio of NAA/Cr in1H-MRS of focal cerebral contusion in rat had significantly decreased since1h after injury.The lowest was24h after injury,then starting to recovere in mild injury group.The ratio did not recovere at1week after injury,and was significantly lower than the mild injury group at all the point in time in severe injury group. Cho/Cr was significantly higher than control group at24h after injury,and started to recovere at1week after injury.The ratio changed more in severe injury group than the mild one.2、Our study detects the concentration of MBP in serum of focal cer-ebral contusion in rat was significantly higher than control group at12h after injury,and the apeak appeared at24h after injury,then starting to dec- rease.The concentration increased more,but decreased less keeping a hig-her level in servere injury group than in mild one.3、Cho/Cr and MBP had a significant positive correlation by using Pearson correlation analysis in both mild injury and sereve injury. NAA/Cr and Cho/Cr、MBP had a negative correlation by using Pearson correlation analysis in sereve injury. So we can reflect the concentration of MBP in serum of focal cerebral contusion in rat by1H-MRS,then evaluating the degree of brain contusion. |
PDF Full Text Request