Extravasation of Microspheres in a Rat Model of Silent Brain Infarcts

Stroke. 2019 Jun;50(6):1590-1594. doi: 10.1161/STROKEAHA.119.024975. Epub 2019 Apr 18.


Background and Purpose- We developed a rat model of silent brain infarcts based on microsphere infusion and investigated their impact on perfusion and tissue damage. Second, we studied the extent and mechanisms of perfusion recovery. Methods- At day 0, 15 µm fluorescent microspheres were injected into the right common carotid artery of F344 rats. At days 1, 7, or 28, the brain was removed, cut in 100-µm cryosections, and processed for immunofluorescent staining and analysis. Results- Injection of microspheres caused mild and transient damage to the treated hemisphere, with a decrease in perfused capillary volume at day 1, as compared with the untreated hemisphere. At day 1 but not at days 7 and 28, we observed IgG staining outside of the vessels, indicating vessel leakage. All microspheres were located inside the lumen of the vessels at day 1, whereas the vast majority (≈80%) of the microspheres were extravascular at day 7, and 100% at day 28. This was accompanied by restoration of perfused capillary volume. Conclusions- Microspheres cause mild and transient damage, and effective extravasation mechanisms exist in the brain to clear microsized emboli from the vessels.

Keywords: angiophagy; arterioles; brain infarction; cerebrovascular disorders; microcirculation; rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain Infarction* / chemically induced
  • Brain Infarction* / metabolism
  • Brain Infarction* / pathology
  • Disease Models, Animal
  • Male
  • Microspheres*
  • Rats
  • Rats, Inbred F344