Biliary injury and regeneration following DAPM toxicity. (A) Serum bilirubin levels indicative of biliary injury after DAPM (50 mg/kg) administration in F344 rats over a time course. * indicates statistical difference from the 0h control (P ≤ 0.05). (B) Histopathology of the liver following DAPM toxicity (50 mg/kg) depicted by H&E staining. Arrow points to the biliary injury. (C) Biliary regeneration after DAPM (50 mg/kg) toxicity depicted by PCNA immunohistochemistry. Brown staining indicates PCNA positive cells. Thin arrow indicates regenerating biliary ductules. Arrowhead points to the hepatocyte proliferation. Scale bar = 100 μm.