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This Article Full Text Full Text (PDF) All Versions of this Article: 291/4/H1919    most recent 01061.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Lucitti, J. L. Articles by Keller, B. B. Search for Related Content PubMed PubMed Citation Articles by Lucitti, J. L. Articles by Keller, B. B.

Increased arterial load alters aortic structural and functional properties during embryogenesis

¹Division of Pediatric Cardiology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania; ²Cell Biology and Anatomy and the Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston, South Carolina; ³Magee-Womens Research Institute, Pittsburgh, Pennsylvania

Submitted 6 October 2005 ; accepted in final form 11 April 2006

As in the adult dorsal aorta, the embryonic dorsal aorta is an important determinant of cardiovascular function, and increased stiffness may have secondary effects on cardiac and microcirculatory development. We previously showed that acutely and chronically increased arterial load via vitelline artery ligation (VAL) increases systemic arterial stiffness. To test the hypothesis that local dorsal aortic stiffness also increases, we measured aortic pulse-wave velocity (PWV) and assessed the active and passive properties (stress and strain) of isolated aortic segments. PWV along the dorsal aorta increased acutely and chronically after VAL. Analysis of isolated aortic active properties suggests that load-exposed aortas experienced higher stress, but not strain, at similar intraluminal pressures. When smooth muscle tone was relaxed, strain decreased in VAL vessels, whereas stress became similar to control vessels. Immunohistochemical analysis revealed that although aortic smooth muscle -actin content was similar between groups, more cell layers expressed smooth muscle -actin, and myocyte cell shape was markedly rounder in VAL embryos. Additionally, aortic and perivascular collagen type I and III content significantly increased in load-exposed VAL vessels. Increased production of these proteins is consistent with the observed increase in aortic PWV and decreased strain in VAL passive aortic segments. Thus the embryonic dorsal aorta is sensitive to increased arterial load and adapts by altering its material properties via changes in collagen content.

arterial mechanics; pulse-wave velocity; chick; collagen