Yn. Fang et al., Changes after dynamic observation of ultrastructural cerebral infarction in renovascular hypertensive rats, CHIN MED J, 113(6), 2000, pp. 520-524
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.