目的：建立新生大鼠脑室周围白质软化 (periventricular leukomalacia，PVL) 模型，探讨PVL新生大鼠脑组织ephrin-B3 mRNA表达以及神经元凋亡的变化及意义。方法：采用2日龄SD清洁级大鼠，通过结扎右侧颈总动脉并吸入6%氧气4 h建立PVL模型，分别于模型后0，8，24，48，72 h、7 d处死，同时设立相应假手术对照组。脑组织苏木精-伊红染色检测病理变化；DAPI染色检测细胞凋亡，荧光定量RT-PCR检测ephrin-B3 mRNA表达。结果：新生大鼠PVL后，脑白质ephrin-B3 mRNA在缺氧缺血后表达增加，与对照组比较，在8，24，48，72 h和7 d有统计学意义（P<0.05），脑组织细胞凋亡在缺氧缺血后明显增加，与对照组相比，在8，24，48，72 h有统计学意义（P<0.05）。结论：新生大鼠PVL时，脑白质ephrin-B3 mRNA表达显著增加，脑组织细胞凋亡明显增加，ephrin-B3可能是神经细胞凋亡的重要因素之一。［中国当代儿科杂志，2007，9（4）：321-323］

OBJECTIVE: To study the changes of ephrin-B3 mRNA expression and cellular apoptosis in the brain of neonatal rats with periventricular leukomalacia (PVL) and to explore the possible role of ephrin-B3 in the pathogenesis of PVL. METHODS: Two-day-old SD rats were randomly assigned to two groups: PVL and control. PVL model was prepared by right common carotid artery ligation followed by 4-hr 6% oxygen exposure. The control group, without ligation of the artery and hypoxia treatment, was sham operated. The rats were then sacrificed and brain tissues were collected at 0, 8, 24, 48 and 72 hrs and at 7 days of hypoxic-ischemia (HI). Hematoxylin and eosin staining was used for pathologic studies. Real time RT-PCR was applied to detect brain ephrin-B3 mRNA expression. DAPI staining was applied to detect neuronal apoptosis. ResultsThe brain ephrin-B3 mRNA expression increased significantly in the PVL group at 8, 24, 48 and 72 hrs and at 7 days of HI compared with that of the control group (P< 0.05). The apoptotic cells in the brain of the PVL group were significantly more than that of the control group at 8, 24, 48 and 72 hrs of HI (P<0.05).CONCLUSIONS: ephrin-B3 mRNA expression and cellular apoptosis in the brain increased significantly in neonatal rats with PVL, which suggests that ephrin-B3 may participate in the pathogenesis of PVL in neonatal rats.