Newborn Rat With Experimental Hypoxic-ischemic Injury Of Brain Tissue Macrophage Inflammatory Protein-1¦Á (mip-1¦Á) Expression

Objective: To set up a model of HIBD and detect the external appearance , pathological and ultrastructural changes of brain in neonatal rat with hypoxic-ischemic brain damage( HIBD). Methods: The 7 day-old SD rats were subjected to the ligation of right carotid artery (ischemia), then they were put into a box filled with 8% dephlogisticated air and 92% nitrogen fums for 2.5 hours (hypoxia). First, the general appearance was observed with naked eyes , then light microscopy and electron microscope was used to detect the brain pathological and ultrastructural changes . Results: Compared with that in the control group, the general appearance of right brain has notable hyperemia and edema at 24 and marked cerebral infarction at 72h after HI. At 6- 24 h after HI,the right hemisphere had distinctly pathological change and infarction was observed at 72h. Neuron lost and glial/inflammatory cell invasion could be seen in the infarction area. Ultrastructural changes showed that some mitochondria swelled significantly at 6h after HI with crista shortened ,even lost.A small quantity neuron had some vacuoles in cytoplasm. At 72h after HI , mitochondria edema were severer than 6h. Chromatin condensed and fragmentation,endoplasmic reticulum dilated and ribosome lost were seen.Conclusions: The generalappearance, pathological and ultrastructural changes were shown apparently in the brain of HIBD rat. which suggested that HIBD model had been setup successfully in neonatal rat.