Morphologic structure of bile canaliculi after bile duct ligation in the rat. A time-course study.

Changes in bile canaliculi (BCs) after bile duct ligation (BDL) are heterogeneous throughout the liver lobule. Male Wistar rats were killed five hours, 20 hours, four days, or eight days after BDL, and BCs were counted according to their shape (1, normal; 2, elongated with microvilli; 3, dilated, devoid of microvilli; or 4, filled with blebs). Compared with controls, the number of BCs doubled after BDL, less than 10% of the BCs were of type 3. As time elapsed, the ratios of types 3 and 4 increased; however, their combined ratio always was below 50%, and remained stable between days 4 and 8. Bilirubin levels peaked between days 2 and 4, then remained stable. The heterogeneous changes in BCs could be explained by the heterogeneous tightness of tight junctions. Decrease in cell size and increase in the size of BC branches could favor contact between bile and blood.