Extracellular Matrix Disarray as a Mechanism for Greater Abdominal Versus Thoracic Aortic Stiffness with Aging in Primates

TY - JOUR

T1 - Extracellular Matrix Disarray as a Mechanism for Greater Abdominal Versus Thoracic Aortic Stiffness with Aging in Primates

AU - Zhang, Jie

AU - Zhao, Xin

AU - Vatner, Dorothy E.

AU - McNulty, Tara

AU - Bishop, Sanford

AU - Sun, Zhe

AU - Shen, You Tang

AU - Chen, Li

AU - Meininger, Gerald A.

AU - Vatner, Stephen F.

N1 - Publisher Copyright: © 2016 American Heart Association, Inc.

PY - 2016/4/1

Y1 - 2016/4/1

N2 - Objective - Increased vascular stiffness is central to the pathophysiology of aging, hypertension, diabetes mellitus, and atherosclerosis. However, relatively few studies have examined vascular stiffness in both the thoracic and the abdominal aorta with aging, despite major differences in anatomy, embryological origin, and relation to aortic aneurysm. Approach and Results - The 2 other unique features of this study were (1) to study young (9±1 years) and old (26±1 years) male monkeys and (2) to study direct and continuous measurements of aortic pressure and thoracic and abdominal aortic diameters in conscious monkeys. As expected, aortic stiffness, β, was increased P<0.05, 2- to 3-fold, in old versus young thoracic aorta and augmented further with superimposition of acute hypertension with phenylephrine. Surprisingly, stiffness was not greater in old thoracic aorta than in young abdominal aorta. These results can be explained, in part, by the collagen/elastin ratio, but more importantly, by disarray of collagen and elastin, which correlated best with vascular stiffness. However, vascular smooth muscle cell stiffness was not different in thoracic versus abdominal aorta in either young or old monkeys. Conclusions - Thus, aortic stiffness increases with aging as expected, but the most severe increases in aortic stiffness observed in the abdominal aorta is novel, where values in young monkeys equaled, or even exceeded, values of thoracic aortic stiffness in old monkeys. These results can be explained by alterations in collagen/elastin ratio, but even more importantly by collagen and elastin disarray.

AB - Objective - Increased vascular stiffness is central to the pathophysiology of aging, hypertension, diabetes mellitus, and atherosclerosis. However, relatively few studies have examined vascular stiffness in both the thoracic and the abdominal aorta with aging, despite major differences in anatomy, embryological origin, and relation to aortic aneurysm. Approach and Results - The 2 other unique features of this study were (1) to study young (9±1 years) and old (26±1 years) male monkeys and (2) to study direct and continuous measurements of aortic pressure and thoracic and abdominal aortic diameters in conscious monkeys. As expected, aortic stiffness, β, was increased P<0.05, 2- to 3-fold, in old versus young thoracic aorta and augmented further with superimposition of acute hypertension with phenylephrine. Surprisingly, stiffness was not greater in old thoracic aorta than in young abdominal aorta. These results can be explained, in part, by the collagen/elastin ratio, but more importantly, by disarray of collagen and elastin, which correlated best with vascular stiffness. However, vascular smooth muscle cell stiffness was not different in thoracic versus abdominal aorta in either young or old monkeys. Conclusions - Thus, aortic stiffness increases with aging as expected, but the most severe increases in aortic stiffness observed in the abdominal aorta is novel, where values in young monkeys equaled, or even exceeded, values of thoracic aortic stiffness in old monkeys. These results can be explained by alterations in collagen/elastin ratio, but even more importantly by collagen and elastin disarray.

KW - abdominal aorta

KW - aging

KW - collagen

KW - elastin

KW - hypertension

KW - nonhuman primates

UR - https://www.scopus.com/pages/publications/84958824544

UR - https://www.scopus.com/pages/publications/84958824544#tab=citedBy

U2 - 10.1161/ATVBAHA.115.306563

DO - 10.1161/ATVBAHA.115.306563

M3 - Article

C2 - 26891739

SN - 1079-5642

VL - 36

SP - 700

EP - 706

JO - Arteriosclerosis, Thrombosis, and Vascular Biology

JF - Arteriosclerosis, Thrombosis, and Vascular Biology

IS - 4

ER -