Nonaka M, Yoshimine T, Kumura E, Kohmura E, Wakayama A, Hayakawa T
Department of Neurosurgery, Osaka University Medical School, Japan.
Neurol Res. 1999 Dec;21(8):771-4. doi: 10.1080/01616412.1999.11741012.
N-acetylaspartate (NAA) is a plausible marker of neuronal viability which decreases in a variety of neurodestructive conditions. To elucidate the mechanism that leads to NAA decline in two different types of cerebral ischemia in rats, we simultaneously determined cortical concentrations of NAA and its hydrolytic metabolites, aspartate, and acetate by high-resolution 1H-NMR spectroscopy. NAA decreased almost linearly up to 24 h in both decapitation induced global cerebral ischemia, and in ischemic cortices of focal ischemia. Acetate was increased continuously for up to 24 h of global ischemia, while in focal cerebral ischemia it was increased transiently at 6 h. Aspartate did not show any change in global ischemia, while it was decreased in focal ischemia. Although NAA decreased similarly in the brain with global and focal ischemia, temporal changes of two NAA hydrolytic metabolites were different in each type of ischemia. The present results suggest hydrolytic degradation of NAA may be modified alternatively under each pathophysiologic condition.
N-乙酰天门冬氨酸（NAA）是一种合理的神经元存活标志物，在多种神经破坏性疾病中会减少。为了阐明大鼠两种不同类型脑缺血导致NAA下降的机制，我们通过高分辨率1H-NMR光谱同时测定了皮质中NAA及其水解代谢产物天门冬氨酸和乙酸盐的浓度。在断头诱导的全脑缺血以及局灶性缺血的缺血皮质中，NAA在长达24小时内几乎呈线性下降。在全脑缺血长达24小时的过程中，乙酸盐持续增加，而在局灶性脑缺血中，乙酸盐在6小时时短暂增加。天门冬氨酸在全脑缺血中没有任何变化，而在局灶性缺血中则减少。尽管在全脑缺血和局灶性缺血的大脑中NAA下降情况相似，但每种缺血类型中两种NAA水解代谢产物的时间变化不同。目前的结果表明，在每种病理生理条件下，NAA的水解降解可能会有所不同。
