Sidhu R S, Tuor U I, Del Bigio M R
Biosystems, Institute for Biodiagnostics, National Research Council Canada, Winnipeg, Canada.
Neurosci Lett. 1997 Feb 21;223(2):129-32. doi: 10.1016/s0304-3940(97)13426-7.
Apoptotic cell death is associated with condensation and fragmentation of the nuclear chromatin into apoptotic bodies. Such nuclei occur frequently following cerebral hypoxia-ischemia in 1 week old rats but seem sparse in older animals. We investigated the age dependence by counting pyknotic or punctate chromatin containing cells in the cerebral cortex of 1,2 and 4 week old animals subjected to cerebral hypoxia-ischemia. In 1 week old animals the majority of injured neurons in the cortex had nuclei with punctate condensed chromatin but few were pyknotic. In the 2 and 4 week old animals the majority of injured cells were pyknotic (P < 0.002). Electron microscopic studies demonstrated the presence of apoptotic bodies. The results suggest that immature brain retains a part of the developmental cell death "program' that is activated following hypoxia-ischemia.
凋亡性细胞死亡与核染色质浓缩和断裂形成凋亡小体有关。这种细胞核在1周龄大鼠脑缺氧缺血后经常出现，但在年龄较大的动物中似乎很少见。我们通过对1周龄、2周龄和4周龄脑缺氧缺血动物大脑皮质中含固缩或点状染色质的细胞进行计数来研究年龄依赖性。在1周龄动物中，皮质中大多数受损神经元的细胞核具有点状浓缩染色质，但固缩的很少。在2周龄和4周龄动物中，大多数受损细胞是固缩的（P<0.002）。电子显微镜研究证实了凋亡小体的存在。结果表明，未成熟脑保留了一部分发育性细胞死亡“程序”，该程序在缺氧缺血后被激活。
