**2.1 Statistics**

Values are presented as mean ± SEM. The percentage changes in wall thickness, cross-sectional area and blood flow were analysed using two-way ANOVA; Fisher's LSD multi-comparisons were performed for the different segments and for the time effect. Linear regression and the parametric Pearson test were computed in a two-tailed manner. Analyses were performed using Prism software. Values were considered significantly different when p < 0.05.
