Effects of apelin on endothelial dysfunction in diabetic APJΔEC mice. (A) Representative images of immunohistochemistry for CD31, CD68, VEGFR-2, Tie-2, ICAM-1, VCAM-1 and E-cadherin in heart sections from APJfl/fl and APJΔEC mice with or without apelin treatment as quantified in (B, C, D, E, F, G and H) (n = 6 mice per group, *P < 0.05). Scale bars represent 50 μm.