Changes after dynamic observation of ultrastructural cerebral infarction in renovascular hypertensive rats

Objective To study the ultrastructural damages of brain tissues dynamically after middle cerebral artery obstruction (MCAO). Methods A middle cerebral artery obstruction (MCAO) model was reproduced in renal vascular hypertensive rats (RHR). Brain tissues in different locatio ns were collected for eight times in row, from two hours to seven days afte r establishment of the animal model. Results The changes occurred in the whole brain after focal cerebral ischem ia. The severity of impairment and time of emergence differed with the loca tion sampled. The earliest in the infarcted region with necrosis was consid ered the major change and completely irreversible damage. The next was seen in marginal regions, mainly with microvascular collapse, formation of micr othrombi, and partial necrosis of brain cells and was considered partially reversible damage. The last was in distant and contralateral hemisphere, ma inly with reversible swelling of endothelial cells and astrocytes. Changes in the MCAO models reproduced by RHR models were much similar to the clinic al pathological changes in cerebral infarction based on the hypertensive ce rebrovascular impairment, and it was regarded as a relatively ideal model f or studying focal ischemic cerebral impairment. Conclusion Dynamic changes of cerebral ultrastructure in which microvascula r impairment plays an important role suggest that clinical therapy cannot o nly be focused on infarction foci, but also on the whole brain with compreh ensively effective measurements.