Recovery of Hypoxic Regions in a Rat Model of Microembolism

J Stroke Cerebrovasc Dis. 2021 Jun;30(6):105739. doi: 10.1016/j.jstrokecerebrovasdis.2021.105739. Epub 2021 Mar 23.

Abstract

Objectives: Endovascular treatment (EVT) has become the standard of care for acute ischemic stroke. Despite successful recanalization, a limited subset of patients benefits from the new treatment. Human MRI studies have shown that during removal of the thrombus, a shower of microclots is released from the initial thrombus, possibly causing new ischemic lesions. The aim of the current study is to quantify tissue damage following microembolism.

Materials and methods: In a rat model, microembolism was generated by injection of a mixture of polystyrene fluorescent microspheres (15, 25 and 50 µm in diameter). The animals were killed at three time-points: day 1, 3 or 7. AMIRA and IMARIS software was used for 3D reconstruction of brain structure and damage, respectively.

Conclusions: Microembolism induces ischemia, hypoxia and infarction. Infarcted areas persist, but hypoxic regions recover over time suggesting that repair processes in the brain rescue the regions at risk.

Keywords: Hypoxia; Infarction; Ischemia; Microembolism; Stroke.

Publication types

  • Video-Audio Media

MeSH terms

  • Animals
  • Brain / blood supply*
  • Brain Infarction / blood
  • Brain Infarction / etiology*
  • Brain Infarction / pathology
  • Brain Infarction / physiopathology
  • Brain Ischemia / blood
  • Brain Ischemia / etiology*
  • Brain Ischemia / pathology
  • Brain Ischemia / physiopathology
  • Cerebrovascular Circulation*
  • Disease Models, Animal
  • Female
  • Hypoxia, Brain / blood
  • Hypoxia, Brain / etiology*
  • Hypoxia, Brain / pathology
  • Hypoxia, Brain / physiopathology
  • Intracranial Embolism / blood
  • Intracranial Embolism / complications*
  • Intracranial Embolism / pathology
  • Intracranial Embolism / physiopathology
  • Male
  • Oxygen / blood*
  • Rats
  • Rats, Wistar
  • Recovery of Function
  • Time Factors

Substances

  • Oxygen