Leptin enhances fibrosis markers at protein level in multidrug resistance protein 2 knockout (Mdr2KO) mice. A–F: Immunohistochemical (IHC) images of liver fibrosis markers and the results of their quantification by image analysis are shown for desmin (A and B), α-smooth muscle actin (α-SMA; C and D), and Sirius Red staining for collagen type I and III (E and F), in liver sections from Mdr2KO and FVB/NJ (FVBN) mice treated with vehicle or leptin. A and C: Arrows point to desmin and α-SMA, respectively. N = 6 (B, D, and F). ∗P < 0.05 for leptin versus vehicle; †P < 0.05 for Mdr2KO versus FVBN mice. Scale bars = 100 μm (A, C, and E).