Hemodynamic stresses and structural remodeling of anastomosing arteriolar networks: design principles of collateral arterioles.
OBJECTIVE
To investigate the potential influence of hemodynamic stresses on the development of the arcade arteriole (AA) network during normal maturation.


METHODS
AA network data were collected from ink-filled Wistar-Kyoto rat gracilis muscles and used to construct hemodynamic computational models of the AA network at 7 (WKY(7)) and 13 (WKY(13)) weeks of age.


RESULTS
Mean coefficients of variation for pressure, circumferential wall stress, and wall shear stress were 0.13, 0.12, and 0.48, respectively. Wall shear rate variability across bifurcations generated deviations in mean energy cost that were 9-30% above theoretical minimum, with many bifurcations exhibiting substantially higher energy costs. With the exception of the lowest pressure AA segments, the monotonic relationship between wall shear stress and pressure in the AAs was nearly identical from 7 to 13 weeks of age.


CONCLUSIONS
Low coefficients of variation for computed AA pressures indicate that an even pressure head is maintained over the muscle during remodeling of the AA network. The anastomotic structure of the network creates high shear rate variability that, in turn, creates high-energy costs in some regions of the network. The results are consistent with the hypothesis that, during development, the maintenance of mean circumferential wall stress and the pressure-shear stress relationship are operative design principles for collateral arteriole development.
Price
Richard J
RJ
Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908-0759, USA. rprice@virginia.edu
Less
Joanne R
JR
Van Gieson
Eric J
EJ
Skalak
Thomas C
TC
D000818:Animals; D001160:Arterioles / Q000254:growth & development* / Q000502:physiology*; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D018482:Muscle, Skeletal / Q000098:blood supply; D051381:Rats; D011921:Rats, Inbred WKY; D013314:Stress, Mechanical