Figure 1:

Animal study flowchart. Seven leptin receptor–deficient (db/db) mice were either injected intraperitoneally (i.p.) with lipopolysaccharid (n = 3) or saline (n = 4) to study endotoxin-induced steatohepatitis. Molecular MR imaging with MPO-Gd performed 18 hours after injection. Livers were then harvested for immunohistochemistry against MPO. For diet-induced hepatitis, 13 db/db mice were fed methionine and choline-deficient (MCD, n = 8)) or control diet (n = 5) for 4 weeks. Then, MR imaging with MPO-Gd or gadopentetate dimeglumine was performed, and livers harvested for immunohistochemistry against MPO, MPO activity assay, and MPO enzyme-linked immmunosorbent assay. Also, three MPO knockout mice were fed MCD diet for 4 weeks and imaged with MPO-Gd.