不同葡萄糖水平对缺氧缺血新生大鼠脑病理改变的影响

Influence of different blood glucose levels on cerebral pathology in neonatal rats with hypoxic ischemia

目的电镜下观察葡萄糖水平对缺氧缺血(HI)新生大鼠脑皮质和海马病理改变的影响。方法7日龄SD新生大鼠随机分为单纯HI组、HI前高血糖组、HI前低血糖组以及正常对照组。各组于HI后72h断头处死,脑组织置2%戊二醛溶液中固定,透射电镜下待检。结果单纯HI主要引起海马部位的病理改变,皮质病变相对轻微。HI前低血糖组的脑病理改变呈进一步加剧,海马部位多见神经元坏死,皮质及海马神经元内线粒体空泡变明显,核周细胞器减少或消失。HI前高血糖组的脑病理改变明显轻于单纯HI组和HI前低血糖组,未见神经元坏死,仅表现为线粒体轻度肿胀以及胶质细胞明显增生。结论HI前低血糖可进一步加剧新生大鼠的脑缺氧缺血损害。

Objectives To explore the influence of different blood glucose levels on cerebral pathology in neonatal rats with hypoxic ischemia（HI）. Methods Seven-day-old neonatal SD rats were randomly divided into 4 groups including normal group, HI group, group with hyperglycemia before HI and group with hypoglycemia before HI. Cerebral pathology in all neonatal rats at 72 h after HI was studied by transmission electron microscopy. Results Hypoxic ischemia resulted in obvious pathological changes in the hippocampus and mild changes in the cortical layer. The cerebral pathological change was aggravated by hypoglycemia before HI. Neuronal necrosis was detected mostly in hippocampus. Observation on hippocampus and cortical layer showed organelle diminution and obliteration, mitochondrial vacuolation and breakage with crystal dissolution. Compared to the HI group and the group with hypoglycemia before HI, significantly milder pathological change of mitochondrial in hippocampus was observed without neuronal necrosis in the group with hyperglycemia before HI. Conclusions It is concluded that hypoglycemia before HI can aggravate cerebral damage while hyperglycemia before HI can obviously alleviate cerebral damage in neonatal rats with HI.