Reperfusion Cellular Injury in an Animal Model of Transient Ischemia
Seung-Koo Leea,
Dong Ik Kima,
Si Yeon Kima,
Dong Joon Kima,
Jong Eun Leeb and
Jae Hwan Kimb
a Department of Radiology, Research Institute of Radiologic Science, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
b the Department of Anatomy, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
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FIG 1. Postreperfusion pattern after recanalization in the MCA occlusion model. Persistent hyperemia (type I hyperperfusion) is observed mainly in the frontal and superior temporal lobes in cats A and B (thick single arrows). Persistent hypoperfusion (type III reperfusion) is seen in the inferior temporal lobe in cat A (double arrows), and early hyperperfusion followed by later hypoperfusion (type II reperfusion) is seen in cat B (thin single arrow).
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FIG 2. Serial changes in the reperfused brain. Initial diffusion-weighted image shows a hyperintense lesion in the striatum, with temporal reversal on the image taken at 24 hours. The lesion becomes a wider area of infarction on diffusion- (white arrow) and T2-weighted images. rCBV maps show hyperperfusion in the striatum, which were shown to normalize on later images (black arrow).
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FIG 3. Findings in the area of persistent hyperperfusion.
A, Serial FLAIR, diffusion-weighted, and perfusion-weighted images show persistent hyperperfusion in the frontal and temporal cortices. Increased rCBV is most prominent the inferior frontal regions (double arrows). Initial FLAIR image shows cortical swelling; however, diffusion-weighted imaging does not depict abnormalities. The last diffusion-weighted images show gradually increasing signal intensity in the affected hemispheric cortex (single arrow), where persistent hyperperfusion is still observed.
B, Light photomicrographs showTUNEL staining. Red-stained areas are not hemorrhagic foci, but highly TUNEL-positive lesions coinciding with areas of hyperperfusion on perfusion-weighted images. HPF images (original magnification x200) show multiple TUNEL-positive cells consisting of neurons and astrocytes. Density of positive cells is higher in affected frontotemporal regions than on the normal side. Red cells are also seen in the striatum that was subjected to normal perfusion and even in the contralateral cortex, but the number was less than that for the lesions. (1 indicates inferior frontal gyrus; 2, superior temporal gyrus; 3, inferior temporal gyrus; 4, striatum; and 5, normal contrlateral cortex.)
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FIG 4. TUNEL-positive cell counts for each region and reperfusion patterns. Type I and II reperfusion had significantly increased TUNEL positivity, whereas type III reperfusion had only slightly increased positivity.
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