Kim Young R, van Meer Maurits P A, Mandeville Joseph B, Tejima Emiri, Dai George, Topalkara Kamil, Qui Jianhua, Dijkhuizen Rick M, Moskowitz Michael A, Lo Eng H, Rosen Bruce R
Athinoula Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
J Cereb Blood Flow Metab. 2007 Jan;27(1):142-53. doi: 10.1038/sj.jcbfm.9600317. Epub 2006 May 17.
Accumulating experimental and clinical data suggest that albumin may be neuroprotective for stroke. Here, we use functional magnetic resonance imaging (fMRI) to evaluate the therapeutic efficacy of albumin and its effects on the recovery of stimuli-induced cerebral hemodynamics. For this purpose, fMRI activity in the ipsilesional somatosensory (SS) cortex was assessed using a well established rat model of transient 90 min focal ischemia and electrical forelimb stimulation. Rats were treated with either saline or albumin via intracerebroventricular injections at 12 h post-stroke onset. Despite this delayed treatment time, when compared to the saline-treated rats (n=7), there were significant enhancements of the fMRI activation in the albumin-treated rats (n=6) for both blood oxygenation level dependence (BOLD) and functional cerebral blood volume (fCBV) responses. Interestingly, the temporal characteristics of the ipsilesional SS BOLD responses in the albumin-treated rats appeared considerably altered compared to those of contralesional responses while such temporal alterations were not pronounced for the fCBV responses. These characteristic fMRI temporal profiles of the albumin-treated brains may be due to altered neuronal responses rather than altered integrity of neurovascular coupling, which implies an unusually fast habituation of neuronal responses in the lesional SS cortex. The correlation between various MRI-derived structural parameters and the fMRI response magnitude was also characteristic for albumin and control groups. Taken together, these data suggest that restoration of fMRI response magnitudes, temporal profiles, and correlations with structure may reveal the extent and specific traits of albumin treatment associated stroke recovery.
越来越多的实验和临床数据表明，白蛋白可能对中风具有神经保护作用。在此，我们使用功能磁共振成像（fMRI）来评估白蛋白的治疗效果及其对刺激诱导的脑血流动力学恢复的影响。为此，我们使用成熟的大鼠短暂性90分钟局灶性缺血和前肢电刺激模型，评估患侧体感（SS）皮层的fMRI活动。中风发作后12小时，通过脑室内注射，给大鼠注射生理盐水或白蛋白进行治疗。尽管治疗时间延迟，但与注射生理盐水的大鼠（n = 7）相比，注射白蛋白的大鼠（n = 6）在血氧水平依赖（BOLD）和功能性脑血容量（fCBV）反应方面，fMRI激活均有显著增强。有趣的是，与对侧反应相比，注射白蛋白的大鼠患侧SS的BOLD反应的时间特征似乎有很大改变，而fCBV反应的这种时间改变并不明显。白蛋白治疗组大脑的这些特征性fMRI时间图谱可能是由于神经元反应改变，而非神经血管耦合的完整性改变，这意味着损伤的SS皮层中神经元反应出现异常快速的习惯化。各种MRI衍生的结构参数与fMRI反应幅度之间的相关性在白蛋白组和对照组中也具有特征性。综上所述，这些数据表明，fMRI反应幅度、时间图谱以及与结构的相关性的恢复，可能揭示白蛋白治疗相关的中风恢复程度和特定特征。
