Nitric oxide haemoglobin interaction: A new biochemical hypothesis for signal changes in fMRI
Nitric oxide haemoglobin interaction: A new biochemical hypothesis for signal changes in fMRI
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DOI：
10.1097/00001756-199701200-00017
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发表时间：
1997-01-20
期刊：
影响因子：
1.7
通讯作者：
dIschia, M
中科院分区：
文献类型：
--
作者：
DiSalle, F;Barone, P;dIschia, M
提出了一种新的关于功能磁共振成像（fMRI）中激活诱导信号变化起源的假说，即一氧化氮（NO）与氧合血红蛋白（Hb-O-2）和脱氧血红蛋白（Hb）反应，瞬时形成顺磁性物质，即高铁血红蛋白（Hb（+））和亚硝基血红蛋白（Hb-NO）。当用T1-、T2-和T2* 加权MRI检查时，发现红细胞中产生的Hb（+）和Hb-NO产生明显的浓度依赖性信号强度变化。健康志愿者静脉注射抗坏血酸（3 g），以特异性地减少大脑激活过程中形成的任何Hb（+），在标准任务中显著降低fMRI信号变化，表明还原剂产生的不依赖于血流的作用。这些结果打开了一个新的角度对功能磁共振成像评价的生理过程与特定任务激活的大脑结构。
A new hypothesis on the origin of activation-induced signal changes in functional magnetic resonance imaging (fMRI) is presented, involving transient formation of paramagnetic species, i.e. methaemoglobin (Hb(+)) and nitrosylhaemoglobin (Hb-NO), by reaction of nitric oxide (NO) with oxy-(Hb-O-2) and deoxyhaemoglobin (Hb). Hb(+) and Hb-NO, generated in erythrocytes, were found to produce marked concentration-dependent signal intensity changes when examined by T1-, T2- and T2*-weighted MRI. Intravenous administration of ascorbic acid (3 g) to healthy volunteers, to specifically reduce any Hb(+) formed during brain activation, markedly decreased fMRI signal changes during standard tasks, suggesting a blood flow-independent effect produced by the reductant. These results open a new perspective on the fMRI evaluation of physiological processes associated with task-specific activation of brain structures.