This is an Accepted Article that has been peer-reviewed and approved for publication in the The Journal of Physiology, but has yet to undergo copy-editing and proof correction. Please cite this article as an 'Accepted Article'; doi: 10.1113/JP275030. This article is protected by copyright. All rights reserved. Role of fetal nutrient restriction and postnatal catch up growth on structural and mechanical alterations of rat aorta Running title: Fetal undernutrition and aorta mechanical properties 1 Perla Y Gutiérrez-Arzapalo, PhD; 1 Pilar Rodríguez-Rodríguez, PhD; 1 David Ramiro-Cortijo, MSc; 1 Ángel L López de Pablo, PhD; 2 Mª Rosario López-Giménez, PhD; 1 Luis Condezo-Hoyos, PhD; 3 Stephen E Greenwald, PhD; 1 Mª Carmen González, PhD and 1 *Silvia M Arribas, PhD. 1 Department of Physiology and 2 Department of Preventive Medicine, Public Health and Microbiology, Faculty of Medicine, Universidad Autónoma de Madrid (Spain). 3 Blizard Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London (United Kingdom). *Corresponding author: Dr. Silvia M Arribas Department of Physiology Faculty of Medicine Universidad Autónoma de Madrid C/ Arzobispo Morcillo 2, Madrid 28029, Spain E-mail: silvia.arribas@uam.es Tel: (+34) 91 497 6995 FAX: (+34) 914975478 Key words: Collagen; Elastin; Fetal Programming; Hypertension; IUGR; Vascular mechanics; Sexual dimorphism. The Table of Contents category: Cardiovascular.