title: Intravascular pillars and pruning in the extraembryonic vessels of chick embryos.
abstract: To investigate the local mechanical forces associated with intravascular pillars and vessel pruning, we studied the conducting vessels in the extraembryonic circulation of the chick embryo. During the development days 13-17, intravascular pillars and blood flow parameters were identified using fluorescent vascular tracers and digital time-series video reconstructions. The geometry of selected vessels was confirmed by corrosion casting and scanning electron microscopy. Computational simulations of pruning vessels suggested that serial pillars form along pre-existing velocity streamlines; blood pressure demonstrated no obvious spatial relationship with the intravascular pillars. Modeling a Reynolds number of 0.03 produced 4 pillars at approximately 20-μm intervals matching the observed periodicity. In contrast, a Reynolds number of 0.06 produced only 2 pillars at approximately 63-μm intervals. Our modeling data indicated that the combination of wall shear stress and gradient of shear predicted the location, direction, and periodicity of developing pillars.
authors: Laboratory of Adaptive and Regenerative Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors: Grace S
authors: GS
authors: Lee
authors: Nenad
authors: N
authors: Filipovic
authors: Miao
authors: M
authors: Lin
authors: Barry C
authors: BC
authors: Gibney
authors: Dinee C
authors: DC
authors: Simpson
authors: Moritz A
authors: MA
authors: Konerding
authors: Akira
authors: A
authors: Tsuda
authors: Steven J
authors: SJ
authors: Mentzer
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000196:embryology* / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D002642:Chick Embryo / Q000098:blood supply* / Q000378:metabolism; D003198:Computer Simulation; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology; D005321:Extraembryonic Membranes / Q000098:blood supply* / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D010507:Periodicity; D012039:Regional Blood Flow / Q000502:physiology; D013314:Stress, Mechanical