Angiogenesis in the brain during development: the effects of vascular endothelial growth factor and angiopoietin-2 in an animal model.
OBJECTIVE
The goal of this study was to examine the roles of vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) in the formation of blood vessels in the brain in a developmental animal model not routinely used for such a study.


METHODS
Either VEGF, Ang-2, or a combination of the two factors were injected into the optic tectum of 4-day-old quail embryos. Immunohistochemical analysis and laser confocal microscopy were used to observe the effects on endothelial cells in the brain. Vascular endothelial growth factor and Ang-2 had very different effects on the development of blood vessels; the former caused expansion and the latter retraction of these vessels. Treatment with a combination of VEGF and Ang-2 caused retroorbital or intraventricular hemorrhage, and brain blood vessels appeared enlarged and dysmorphic, with dramatically extended filopodia.


CONCLUSIONS
Some of these observations may provide insight into how one may develop a better model of brain arteriovenous malformations.
Vates
G Edward
GE
Department of Neurology, Center for Cerebrovascular Research, University of California, San Francisco, California, USA. edward_vates@urmc.rochester.edu
Hashimoto
Tomoki
T
Young
William L
WL
Lawton
Michael T
MT
D042702:Angiopoietin-2 / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000196:embryology*; D003370:Coturnix; D004625:Embryo, Nonmammalian; D042783:Endothelial Cells / Q000502:physiology; D023421:Models, Animal; D018919:Neovascularization, Physiologic; D042461:Vascular Endothelial Growth Factor A / Q000502:physiology*
D042702:Angiopoietin-2; D042461:Vascular Endothelial Growth Factor A