Fig. 1.

Apelin inhibits abdominal aortic aneurysm (AAA) formation. A: aortic ultrasound 7 days post-elastase infusion revealed reduced in vivo maximal aneurysm diameter with apelin infusion (top) compared with saline infusion (bottom). B: apelin reduced the ultrasonographic aortic diameter by 29% (P < 0.01) and cross-sectional aortic area by 47% (P < 0.03) relative to saline. Representative hematoxylin and eosin (C)- and Verhoeff elastic-Masson's trichrome (D)-stained aortic samples reveal that apelin treatment (top) prevented aneurysmal dilation and inflammatory cell infiltration 1 wk after elastase infusion relative to saline treatment (bottom). Note the reduced leukocyte burden (open arrows) and preserved elastic and collagenous support structure (black arrows) in the apelin group.