Abstract
Hypoxic tissue has been observed in the surrounding areas of the ischemic core following cerebral infarction. The underlying mechanisms for this potentially reversible ischemic region remain to be determined. In this study, we generated permanent brain ischemia (PI) and reperfusion after inducing ischemia for 1.5 h (ischemia–reperfusion or IR) in a rat model of middle cerebral artery occlusion. Using immunofluorescence, we observed hypoxic tissue in ischemic brains and assessed microvessel density in and surrounding the hypoxic tissue. We found that the hypoxic tissues were observed at 1 and 3 days in PI rats and at 1, 3, 7, and 14 days in IR rats. The hypoxic tissue gradually decreased over time. The microvessel density increased in a time-dependent manner in focal brain ischemic tissue in PI and IR rats. Furthermore, IR induced a significant increase in microvessel density when compared with PI rats (P < 0.05). Microvessel density surrounding hypoxic tissue was significantly higher when compared with within the hypoxic tissue (P < 0.05). These data demonstrate that hypoxic tissue may exist for a long period (14 days) following brain IR and indicate that hypoxic tissue usually existed with low microvessel density. Furthermore, the duration of hypoxic tissue was partially dependent on the degree of microvessel proliferation.
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Acknowledgments
The authors thank Prof. Cameron J. Koch (University of Pennsylvania, PA) for his kind gifts (EF5 and Cy3-conjugated ELK3–51 monoclonal antibodies and Cy3- ELK3-51 competed solution). This work was supported by Science and Technology Planning Project of Guangdong Province, China (No. 2007B031502007) to Y. Wang.
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J. Pan and Y. Li contributed equally to this work.
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Pan, Jr., Li, Y., Pei, Z. et al. Hypoxic tissues are associated with microvessel density following brain ischemia–reperfusion. Neurol Sci 31, 765–771 (2010). https://doi.org/10.1007/s10072-010-0441-z
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DOI: https://doi.org/10.1007/s10072-010-0441-z