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[Changes after dynamic observation of ultrastructural cerebral infarction in renovascular hypertensive rats]
1Department of Neurology, First Affiliated Hospital, Sun Yat-Sen University of Medical Sciences, Guangzhou 510080, China. dyzhu@sti.gd.cn
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 locations were collected for eight times in row, from two hours to seven days after establishment of the animal model.
Results:
The changes occurred in the whole brain after focal cerebral ischemia. The severity of impairment and time of emergence differed with the location sampled. The earliest in the infarcted region with necrosis was considered the major change and completely irreversible damage. The next was seen in marginal regions, mainly with microvascular collapse, formation of microthrombi, and partial necrosis of brain cells and was considered partially reversible damage. The last was in distant and contralateral hemisphere, mainly with reversible swelling of endothelial cells and astrocytes. Changes in the MCAO models reproduced by RHR models were much similar to the clinical pathological changes in cerebral infarction based on the hypertensive cerebrovascular impairment, and it was regarded as a relatively ideal model for studying focal ischemic cerebral impairment.
Conclusion:
Dynamic changes of cerebral ultrastructure in which microvascular impairment plays an important role suggest that clinical therapy cannot only be focused on infarction foci, but also on the whole brain with comprehensively effective measurements.
Insights
This study reveals dynamic ultrastructural brain changes after middle cerebral artery obstruction (MCAO). Microvascular damage is key, indicating therapy should target the whole brain, not just infarction foci.
Area of Science:
- Neuroscience
- Pathology
- Vascular Biology
Context:
- Middle cerebral artery obstruction (MCAO) is a common model for studying ischemic stroke.
- Renal vascular hypertensive rats (RHR) offer a relevant model for cerebrovascular disease.
- Understanding dynamic ultrastructural changes is crucial for stroke research.
Purpose:
- To dynamically investigate ultrastructural brain tissue damage following middle cerebral artery obstruction (MCAO).
- To characterize the temporal and spatial progression of cellular and microvascular changes post-MCAO.
Summary:
- Focal cerebral ischemia induces widespread brain changes, varying by location and severity.
- Infarcted regions show irreversible necrosis; marginal regions exhibit partially reversible damage with microvascular collapse.
- Distant and contralateral hemispheres display reversible endothelial and astrocyte swelling.
Impact:
- The study highlights the critical role of microvascular impairment in ischemic stroke.
- Findings suggest that clinical stroke therapy requires a comprehensive approach, addressing the entire brain beyond infarction foci.
- This research provides insights into stroke pathophysiology and potential therapeutic targets.