Silberstein Morry, Lane Dianne, Dodd Seetal, Opeskin Kenneth
Department of Radiology, University of Sydney, School of Medicine, Monash University, Australia.
AJNR Am J Neuroradiol. 2002 Mar;23(3):389-92.
Laboratory studies have been used to identify nitric oxide as a notable mediator in neuronal death after acute brain injury. To our knowledge, this has not previously been confirmed with in vivo study in humans. Our purpose was to seek in vivo evidence for the induction of nitric oxide synthase (NOS) in human acute brain injury by using proton MR spectroscopy.
In vitro proton MR spectra were obtained in neural extracts from 30 human cadavers, and in vivo spectra were obtained in 20 patients with acute brain injury and in a similar number of control subjects.
We identified a unique peak at 3.15 ppm by using in vivo proton MR spectroscopy in eight of 20 patients with acute brain injury but not in 20 healthy volunteers (P <.002). On the basis of in vitro data, we have tentatively assigned this peak to citrulline, a NOS by-product.
To our knowledge, our findings suggest, for the first time, that excitotoxicity may occur in human acute brain injury. Confirmation with the acquisition of spectra in very early acute cerebral injury would provide a rationale for the use of neuroprotective agents in these conditions, as well as a new noninvasive method for quantification.
实验室研究已将一氧化氮确定为急性脑损伤后神经元死亡的重要介质。据我们所知，此前尚未在人体的体内研究中得到证实。我们的目的是通过质子磁共振波谱法寻找人体急性脑损伤中一氧化氮合酶（NOS）诱导的体内证据。
从30具人类尸体的神经提取物中获取体外质子磁共振波谱，并在20例急性脑损伤患者及数量相近的对照受试者中获取体内波谱。
我们通过体内质子磁共振波谱在20例急性脑损伤患者中的8例中识别出了一个位于3.15 ppm的独特峰，但在20名健康志愿者中未发现（P <.002）。根据体外数据，我们初步将该峰归为瓜氨酸，一种NOS的副产物。
据我们所知，我们的研究结果首次表明，兴奋性毒性可能在人体急性脑损伤中发生。在极早期急性脑损伤中获取波谱进行确认，将为在这些情况下使用神经保护剂提供理论依据，以及一种新的无创定量方法。
