Hwang In Koo, Yoo Ki-Yeon, Kim Dae Won, Kwon Oh-Shin, Lim Soon Sung, Kang Il-Jun, Choi Soo Young, Won Moo-Ho
Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, South Korea.
Neurochem Res. 2008 Jul;33(7):1356-64. doi: 10.1007/s11064-008-9591-2. Epub 2008 Feb 21.
Pyridoxal 5'-phosphate (PLP) is an important cofactor in a wide range of biochemical reactions, such as the metabolism of various amino acids, including GABA. PLP is synthesized by the oxidation of pyridoxine 5'-phosphate (PNP), which is catalyzed by PNP oxidase (PNPO). We observed the changes in cresyl violet-positive neurons, PNPO immunoreactivity and PNPO protein levels in the somatosensory cortex and striatum in gerbils after 5 min of transient forebrain ischemia. Cresyl violet-positive neurons showed condensed cytoplasm in the somatosensory cortex and lateral part of the striatum at 2 days after ischemia/reperfusion. PNPO immunoreactivity began to increase in neurons in layers III and V at 3 h after ischemia/reperfusion and this immunoreactivity was significantly increased at 12 h after ischemia/reperfusion. Thereafter, PNPO immunoreactivity decreased with time after ischemia/reperfusion. PNPO-immunoreactive neurons were only slightly detected in the lateral part of the striatum at 12 h after ischemia/reperfusion. In addition, the PNPO protein levels in both the somatosensory cortex and striatum homogenates peaked at 12 h after ischemia/reperfusion. These results indicate that PNPO is significantly increased in the ischemic somatosensory cortex and lateral part of the striatum, and this change in the level of PNPO may be associated with the neuronal damage induced by ischemia.
磷酸吡哆醛（PLP）是多种生化反应中的重要辅助因子，如包括γ-氨基丁酸（GABA）在内的各种氨基酸的代谢。PLP由磷酸吡哆醇（PNP）氧化合成，此过程由PNP氧化酶（PNPO）催化。我们观察了沙土鼠短暂性前脑缺血5分钟后，其体感皮层和纹状体中甲基紫阳性神经元、PNPO免疫反应性及PNPO蛋白水平的变化。缺血/再灌注2天后，甲基紫阳性神经元在体感皮层和纹状体外侧部显示出细胞质浓缩。缺血/再灌注3小时后，PNPO免疫反应性开始在III层和V层神经元中增加，且在缺血/再灌注12小时时这种免疫反应性显著增强。此后，缺血/再灌注后PNPO免疫反应性随时间下降。缺血/再灌注12小时时，仅在纹状体外侧部轻微检测到PNPO免疫反应性神经元。此外，体感皮层和纹状体匀浆中的PNPO蛋白水平在缺血/再灌注12小时时达到峰值。这些结果表明，缺血的体感皮层和纹状体外侧部中PNPO显著增加，且PNPO水平的这种变化可能与缺血诱导的神经元损伤有关。
