Age-related changes in the morphology and mechanics of arterial wall in the rat

Abstract

This study was done to know the effects of aging on arterial mechanics from the viewpoint of tissue remodeling. Rats at growing (8 and 16 weeks), maturated (32 weeks) and middle (64 weeks) ages were used. After blood pressure and blood flow were measured in the abdominal aorta and common carotid artery, respectively, the carotid artery was excised to obtain pressure-diameter relations and wall dimensions. Although blood pressure increased during growth and blood flow gradually increased with age, wall hoop stress and wall shear stress showed no significant changes except for a decrease in wall shear stress during growth, which was attributable to morphological changes of wall. Wall stiffness and elastic properties at in vivo pressure did not significantly change until maturation; however, they increased by middle age.