Scale of adaptive arteriogenesis. (A,B) Representative images of the LV free wall myocardium of post-MI male and female rats immunofluorescence-stained with an antibody against smooth muscle α-actin (red color) and DAPI (blue). (C) Arteriolar length density relative to a vessel diameter group in the LV free wall and septum. (D) Arteriolar volume density relative to a vessel diameter group in the LV free wall and septum. Scale bars are 20 μm. Values are the mean ± SEM; n = 7 male rats/group; n = 6 female rats/group. *P < 0.05 vs. a corresponding sham group; §§P < 0.01 and §§§P < 0.001 vs. M-Sham rats; †P < 0.05 and †††P < 0.001 vs. M-MI rats.