Pathological changes of brain tissue in a rat model with coexistence of hyperlipidemia and cerebral ischemia / 中国组织工程研究

ABSTRACT

BACKGROUND:Cerebral ischemia often occurs in underlying pathological conditions, such as hypertension, hyperlipidemia and diabetes. Therefore, it is of great significance to construct a cerebral ischemia rat model with hyperlipidemia and to study the effect of basic pathological changes on the cerebral ischemia. OBJECTIVE:To observe the brain tissue pathological changes of rat models with coexistence of hyperlipidemia and cerebral ischemia, and the effect of hyperlipidmia on cerebral ischemia. METHODS:The rats were fed with high-fat diet to establish the hyperlipidmia models, and then focal cerebral ischemia models were prepared with suture method. At 3 and 7 days after modeling, the 2,3,5-triphenyltetrazolium chloride staining was used to observe the volume of brain tissue ischemia, and hematoxylin-eosin staining was performed to observe pathological change of the margin of the brain tissue ischemia zone. RESULTS AND CONCLUSION:2,3,5-Triphenyltetrazolium chloride staining staining results showed that the volume of cerebral ischemia was significantly reduced in the hyperlipidemia+cerebral ischemia 7 day group. Hematoxylin-eosin staining results showed there was typical ischemic changes in al the cerebral ischemia models, and the number of microglial cel s after cerebral ischemia for 7 days was significantly smal er than that after cerebral ischemia for 3 days, and the changes were more obvious in the hyperlipidemia+7-day cerebral ischemia group when compared with the hyperlipidemia+3-day cerebral ischemia group. Ultrastructure showed there were neuronal and glial nuclear membrane shrinkage in al the cerebral ischemia models, mitochondria cristae was disappeared completely, endothelial cel mitochondria was decreased, most of the synaptic vesicles of nerve synapse were dissolved;the damages above were improved after ischemia for 7 days, especial y hyperlipidemia+cerebral ischemia for 7 days, the neuronal degeneration and necrosis were reduced, the mitochondrial damage was repaired, the number of mitochondrial cristae was increased significantly, and the synaptic vesicles of nerve synapse were recovered significantly. The results indicate that hyperlipidemia can promote the recovery of cerebral ischemic injury, probably because the hyperlipidemia factors can activate the protection mechanism.