DTI对脑梗死大鼠下调脑区激活的动态评估

Temporal Assessment of Functional Down-Regulation Area in Rats with Cerebral Infarction by DTI

目的探讨DTI对脑梗死大鼠下调脑区激活的动态评估。方法 120只成年雄性SD大鼠,随机分为假手术组,模型组,生理盐水组,丁苯酞干预组。选取缺血后1 h、3 h、6 h、12 h、24 h,进行神经功能评分,MRI扫描,免疫组织化学观察RGMa蛋白的表达情况。结果 (1)MCAO模型组、生理盐水组大鼠缺血后,不同时间点小脑半球的RGMa蛋白阳性表达均有所增加。丁苯酞组在相应时间点的RGMa蛋白的表达较MCAO模型组有所降低,在1 h、3 h、6 h、12 h差异具有统计学意义。(3)MCAO模型组、生理盐水组大鼠小脑半球缺血后1 h后,各个时间点FA值较假手术组降低,均具有统计学差异(P<0.05);丁苯酞组大鼠小脑半球FA值较MCAO模型组升高,在3 h、6 h、12 h、24 h时间点两组间的FA值差异具有统计学意义(P<0.05)。(3)各手术组大鼠的m NSS神经功能评分与小脑半球RGMa蛋白表达存在正相关,与FA值呈负相关。结论 DTI可以动态评估脑梗死大鼠下调脑区的激活,为临床预后评估提供影像学依据。

Objective To evaluate the cerebral area of functional down-regulation by DTI in rats.Methods 140 healthy male SD rats were randomly divided into the following four groups：sham operation group,MCAO model group,saline group and the experimental group.The modified neurological severity score,magnetic resonance exam and Western blot assay RGMa expression of the cerebellum were performed at 1 h,3 h,6 h,12 h,24 h after successful MCAO model.Results 1.After ischemia,RGMa protein expression of MCAO model group and saline group in ischemic area had increased,RGMa expression gradually increased over time,up to maximum at 12 h;RGMa protein expression of NBP group were reduced,difference was statistically significant at 1 h,3 h,6 h,12 h （P 〈 0.05）.2.After ischemia 1 h,the FA values of MCAO model group and saline group decrease compared with sham group,and had significant difference （P 〈 0.05）;The cerebellum FA values of NBP group compared with MCAO model group,the difference between the two groups was statistically significant at 3 h,6 h,12 h,24 h after ischemia （P 〈0.05）.3.RGMa protein expression of cerebellum had positive correlation with mNSS,and FA value had negative correlation.Conclusion DTI could dynamically monitor changes in rats with ischemic stroke and changes after treatment.