A-D, Aneurysmal sections with isotype-matched IgG control (A, B) and cd68-positive immunostaining in an aneurysmal tissue section from an AngII-infused ob/ob mice (C, D). Macrophages are present in adventitia and periaortic adipose tissue. Boxes represent regions illustrated at higher magnification in B, D. E, AngII infusion promotes macrophage infiltration into the stromal vascular fraction of retroperitoneal white adipose tissue from ob/ob mice (n = 5/group). F, Macrophage infiltration into the stromal vascular fraction of white adipose tissue from mice who developed AAAs compared to mice that did not develop AAAs (n = 4 no AAA; n = 3 AAA). Data are mean ± SEM; *, denotes significantly different from saline or no AAA, P < 0.05.