Histomorphometric parameters of aortas isolated from <i>HtrA1</i>^<i>-/-</i> mice.

<p>Cross sections from the upper half of the descending aorta were stained with elastica van Gieson (EVG), hematoxylin and eosin (HE), or picrosirius red. The EVG-stained sections were analyzed for <b>A</b>, cross-sectional area; <b>B</b>, media thickness; <b>C</b>, lumen diameter; the HE-stained sections were analyzed for <b>D</b>, medial VSMC number. Bars represent means ± SD (four to 10 mice were used for each group and 3–8 aorta sections per mouse were analyzed. The details are described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196628#pone.0196628.s010" target="_blank">S2 File</a>). Statistical significance was determined by Student’s <i>t</i>-test. Asterisks show significance between wild type (WT; black bars) and <i>HtrA1</i>^<i>-/-</i> (KO; white bars) mice at the same age (*, p <0.05; **, p <0.01). $ or # show significance (p <0.05) of the difference in medial VSMC numbers between 40- and 52-week-old, or 52- and 60-week-old, <i>HtrA1</i>^<i>-/-</i> mice, respectively.