Further characterisation of a thromboembolic model of stroke in the rat

Brain Res. 2001 Mar 23;895(1-2):18-24. doi: 10.1016/s0006-8993(00)03331-x.

Abstract

We have used magnetic resonance imaging (MRI) techniques to characterise a rat model of thromboembolic stroke. The consequences of acute perfusion deficit associated with a middle cerebral artery occlusion (MCAo) by a newly formed thrombus was mapped by interrogation of the tissue oxygenation status using gradient echo methods and production of T2* maps. Final infarct size was subsequently assessed at 24-h post-ischaemia by histology with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Animals displayed an infarct volume of 178.7+/-84.2 mm(3) (mean+/-S.D.) with a large coefficient of variation (47%) and range of values (85.6--265.5 mm(3)). This variability provided us with an opportunity to assess the relationships between early imaging observations and eventual infarct size. For a single cerebral slice, at the centre of the MCA territory, a relationship between the area of reduced T2* at 1 and 2 h post MCAo correlated highly with final lesion area (Spearman rank correlation, r=0.98, P<0.01, n=9). Lesion volumes in the thromboembolic MCAo model were compared with a 120-min occlusion, 22-h reperfusion protocol using an intraluminal thread MCAo approach. For the thromboembolic model, the total lesion volume was found to be smaller (178.7+/-84.2 vs. 243.3+/-50.1 mm(3), mean+/-S.D., Student's t-test P=0.046) and showed a greater variability (coefficient of variations: 47% vs. 21%). These data underline the relative variability of this embolic model and provide important preliminary information regarding the value of early changes in T2* in predicting eventual infarct size.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Disease Progression
  • Infarction, Middle Cerebral Artery / metabolism
  • Infarction, Middle Cerebral Artery / pathology*
  • Infarction, Middle Cerebral Artery / physiopathology
  • Magnetic Resonance Imaging
  • Male
  • Middle Cerebral Artery / pathology
  • Middle Cerebral Artery / physiopathology
  • Prosencephalon / blood supply
  • Prosencephalon / injuries
  • Prosencephalon / pathology*
  • Rats
  • Rats, Inbred Strains
  • Thromboembolism / metabolism
  • Thromboembolism / pathology*
  • Thromboembolism / physiopathology
  • Time Factors