Double ligature model of the common bile duct in male rats of the Sprague-Dawley strain. (A) Under deep Ketamine-Rompun anesthesia the abdominal wall was shaved and a small incision with a scalpel was made. (B) The abdominal cavity was opened, and selvages were stretched and fixated with two sterile high-grade steel tweezers. (C) Liver lobules were turned down and intestines were carefully pulled out. (D) The common bile duct was fixed with forceps and obstructed with a piece of string. (E) A second ligature was set in a distance of approximately 1 cm. (F) Intestines were into the abdominal cavity and the incision was replaced/sewn by several pinpricks. (G) The livers of sham-operated animals showed no sign of fibrosis at day 12 after surgery. (H) In contrast, in livers of animals receiving bile duct ligature a high degree of hepatic fibrosis is induced. Signs of ongoing liver fibrogenesis are the formation of oedema and fibrotic nodules on the surface of corresponding livers.