title: Analysis of early embryonic great-vessel microcirculation in zebrafish using high-speed confocal μPIV.
abstract: In the developing cardiovascular system, hemodynamic vascular loading is critical for angiogenesis and cardiovascular adaptation. Normal zebrafish embryos with transgenically-labeled endothelial and red blood cells provide an excellent in vivo model for studying the fluid-flow induced vascular loading. To characterize the developmental hemodynamics of early embryonic great-vessel microcirculation in the zebrafish embryo, two complementary studies (experimental and numerical) are presented. Quantitative comparison of the wall shear stress (WSS) at the first aortic arch (AA1) of wild-type zebrafish embryos during two consecutive developmental stages is presented, using time-resolved confocal micro-particle image velocimetry (μPIV). Analysis showed that there was significant WSS difference between 32 and 48 h post-fertilization (hpf) wild-type embryos, which correlates with normal arch morphogenesis. The vascular distensibility of the arch wall at systole and the acceleration/deceleration rates of time-lapse phase-averaged streamwise blood flow curves were also analyzed. To estimate the influence of a novel intermittent red-blood cell (RBC) loading on the endothelium, a numerical two-phase, volume of fluid (VOF) flow model was further developed with realistic in vivo conditions. These studies showed that near-wall effects and cell clustering increased WSS augmentation at a minimum of 15% when the distance of RBC from arch vessel wall was less than 3 μm or when RBC cell-to-cell distance was less than 3 μm. When compared to a smooth wall, the WSS augmentation increased by a factor of ~1.4 due to the roughness of the wall created by the endothelial cell profile. These results quantitatively highlight the contribution of individual RBC flow patterns on endothelial WSS in great-vessel microcirculation and will benefit the quantitative understanding of mechanotransduction in embryonic great vessel biology, including arteriovenous malformations (AVM).
authors.affiliation: Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15219, USA.
authors.forename: Chia-Yuan
authors.initials: CY
authors.lastname: Chen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Patrick
authors.forename: Paola
authors.initials: P
authors.lastname: Corti
authors.forename: William
authors.initials: W
authors.lastname: Kowalski
authors.forename: Beth L
authors.initials: BL
authors.lastname: Roman
authors.forename: Kerem
authors.initials: K
authors.lastname: Pekkan
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology; D001158:Arteries / Q000254:growth & development / Q000502:physiology*; D001783:Blood Flow Velocity; D004625:Embryo, Nonmammalian / Q000098:blood supply*; D047108:Embryonic Development; D004912:Erythrocytes / Q000502:physiology; D006439:Hemodynamics; D040542:Mechanotransduction, Cellular; D008833:Microcirculation; D018613:Microscopy, Confocal; D012212:Rheology; D033081:Shear Strength; D015027:Zebrafish