Reversal blood flow component as determinant of the arterial functional capability: theoretical implications in physiological and therapeutic conditions.
In several physiological, pathological, and therapeutic circumstances, the arterial blood flow is acutely modified, increasing, in some vascular segments the reversal (SSR) and oscillatory (SSO) components of the shear stress. Recently, in an in vivo model we found a relationship between acute changes in SSR and SSO, and variations in the arterial viscoelasticity. As the arterial viscoelasticity and diameter are the main determinants of the arterial buffering (BF) and conduit (CF) functions, changes in those functions could be expected associated with variations in SSR and SSO. The aim was to analyze the association between acute increases in SSR and SSO, and changes in the aortic CF and BF. Aortic flow, pressure, and diameter were measured in 16 sheep under basal and high reversal and oscillatory flow conditions (high SSR and SSO). Aortic BF and CF were quantified, and their potential association with the SSR and SSO components were analyzed. During high reversal flow rate conditions, a smooth muscle contraction-pattern was evidenced, with an increase in BF and a decrease in CF. Changes in BF and CF were associated with the changes in SSR and SSO. The acute effects on the arterial wall biomechanics of variations in SSR and SSO could contribute to comprehend their chronic effects, and the meaning of the acute vascular effects of changes in SSR and SSO would depend on the situation. Increases in SSR and SSO could be associated with smooth muscle tone increase-dependent changes in arterial BF and CF.
Bia
Daniel
D
Physiology Department, School of Medicine, Republic University, Montevideo, Uruguay. dbia@fmed.edu.uy
Zócalo
Yanina
Y
Armentano
Ricardo L
RL
de Forteza
Eduardo
E
Cabrera-Fischer
Edmundo
E
D000818:Animals; D001011:Aorta / Q000502:physiology* / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity; D001794:Blood Pressure; D004548:Elasticity; D006439:Hemodynamics; D008955:Models, Cardiovascular; D012756:Sheep; D013314:Stress, Mechanical