http://jcb.sagepub.com/content/early/2016/10/18/0271678X16674737.abstract?&
- Pavel Yanev1
- Peter R Seevinck1
- Umesh S Rudrapatna1
- Mark JRJ Bouts1
- Annette van der Toorn1
- Karen Gertz2,3
- Golo Kronenberg2,4
- Matthias Endres2,3,4,5,6
- Geralda A van Tilborg1
- Rick M Dijkhuizen1⇑
- 1Biomedical MR Imaging and Spectroscopy Group, University Medical Center Utrecht, Utrecht, The Netherlands
- 2Department of Neurology, Charité – Universitaetsmedizin Berlin, Berlin, Germany
- 3Center for Stroke Research Berlin, Charité – Universitaetsmedizin Berlin, Berlin, Germany
- 4German Center for Cardiovascular Research (DZHK), Universitaetsmedizin Berlin, Berlin, Germany
- 5German Center for Neurodegenerative Diseases (DZNE), Universitaetsmedizin Berlin, Berlin, Germany
- 6Berlin Institute of Health (BIH), Berlin, Germany
- Rick M Dijkhuizen, Center for Image Sciences, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. Email: r.m.dijkhuizen@umcutrecht.nl
Abstract
The pattern of vascular remodelling in
relation to recovery after stroke remains largely unclear. We used
steady-state contrast-enhanced
magnetic resonance imaging to assess the
development of cerebral blood volume and microvascular density in
perilesional and
exofocal areas from (sub)acutely to chronically
after transient stroke in rats. Microvascular density was verified
histologically
after infusion with Evans Blue dye. At day 1,
microvascular cerebral blood volume and microvascular density were
reduced in
and around the ischemic lesion (intralesional
borderzone: microvascular cerebral blood volume = 72 ± 8%; microvascular
density = 76 ± 8%)
(P < 0.05), while total cerebral blood volume
remained relatively unchanged. Perilesional microvascular cerebral blood
volume
and microvascular density subsequently normalized
(day 7) and remained relatively stable (day 70). In remote ipsilateral
areas
in the thalamus and substantia nigra – not part of
the ischemic lesion – microvascular density gradually increased between
days 1 and 70 (thalamic ventral posterior nucleus:
microvascular density = 119 ± 9%; substantia nigra: microvascular
density = 122 ± 8%
(P < 0.05)), which was confirmed histologically.
Our data indicate that initial microvascular collapse, with maintained
collateral
flow in larger vessels, is followed by dynamic
revascularization in perilesional tissue. Furthermore, progressive
neovascularization
in non-ischemic connected areas may offset
secondary neuronal degeneration and/or contribute to non-neuronal tissue
remodelling.
The complex spatiotemporal pattern of vascular
remodelling, involving regions outside the lesion territory, may be a
critical
endogenous process to promote post-stroke brain
reorganization.
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