Macrophage infiltration after UUO in wild-type mice with either Agtr1–/– marrow or Agtr1+/+ marrow. (a) Immunohistochemical demonstration of macrophages with anti-F4/80 antibody in mice with Agtr1–/– marrow (left) and mice with Agtr1+/+ marrow (right) at day 14 after UUO. Magnification, ×400. (b) Macrophages (F4/80-positive cells) infiltrating to the interstitium at day 5 (left) and day 14 (right) after UUO. Black bars represent mice with Agtr1–/– marrow; white bars represent mice with Agtr1+/+ marrow. Data are expressed as means ± SEM. *P < 0.001 for mice with Agtr1–/– marrow versus mice with Agtr1+/+ marrow. NS, not significant.