Rat liver results. (a) Liver weight in bile duct ligated (BDL) or sham-operated rats. Data are shown as mean ± standard error of the mean (SEM). ***P < 0.0001. (b) Scoring of the structural changes in the livers of each group. Data are shown as mean ± SEM. (c) Masson's trichrome photomicrographs showing the hepatic structure in rats 5 weeks after a sham operation (c2), 2 weeks after BDL (c3), 4 weeks after BDL (c4) and 5 weeks after BDL (c5). The structure of the hepatic lobules around the portal tract (arrows) is clearly disrupted in the BDL rats compared with the sham-operated rats. (d) Immunohistochemical analysis of type I collagen. Type I collagen is localised around fibrotic structures. Original magnification × 40 or × 100.