EPR imaging for in vivo analysis of the half-life of a nitroxide radical in the hippocampus and cerebral cortex of rats after epileptic seizures.
EPR imaging for in vivo analysis of the half-life of a nitroxide radical in the hippocampus and cerebral cortex of rats after epileptic seizures.
复制标题
EPR 成像用于体内分析癫痫发作后大鼠海马和大脑皮层中硝基氧自由基的半衰期。
DOI：
10.1016/s0891-5849(99)00093-3
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发表时间：
1999
影响因子：
7.4
通讯作者：
Hitoshi Kamada
中科院分区：
文献类型：
--
作者：
H. Yokoyama;Yijing Lin;O. Itoh;Y. Ueda;A. Nakajima;T. Ogata;Toshiyuki Sato;Hiroaki Ohya;Hitoshi Kamada
最近，我们发展了一种应用于大鼠脑内的在体时间电子顺磁共振成像技术，将血脑屏障可穿透的氮氧自由基3-methoxycarbonyl-2，2，5，5-tetramethylpyrrolidine-1-oxyl(PCAM)注入其中。这种成像技术使得同时测量大脑多个区域中氮氧自由基的衰减率成为可能。利用这项技术，根据红藻氨酸(KA)致痫后大鼠海马区和大脑皮层EPR图像信号强度的指数衰减，估算了PCAM的半衰期。KA致痫后，PCAM的海马半衰期显著延长(P<0.01)，而皮质半衰期延长不明显。这些发现表明，KA发作后，海马区内还原氮氧自由基的能力受损，但大脑皮层的能力完好无损。这是第一个与KA诱导的大脑癫痫发病机制有关的体内定量EPR成像研究。
Recently, we developed an in vivo temporal electron paramagnetic resonance (EPR) imaging technique to be applied to the brain of a rat, into which a blood-brain barrier (BBB)-permeable nitroxide radical, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) was injected intraperitoneally. This imaging technique made it possible to measure decay rates of a nitroxide radical in multiple regions of the brain simultaneously. Using this technique, the half-life of PCAM was estimated from the exponential decay of the signal intensity derived from the temporal EPR images in the hippocampus and cerebral cortex of rats after a kainic acid (KA)-induced seizure. The hippocampal half-life of PCAM after KA-induced seizures was significantly prolonged (p < .01), whereas the prolongation of the cortical half-life was not significant. These findings suggest that following a KA-seizure, the intrahippocampal ability to reduce the nitroxide radical is impaired, but the ability is intact in the cerebral cortex. This is the first in vivo quantitative EPR imaging study that has a bearing on the pathogenesis of KA-induced seizures in the brain.