Unknown bile ductuli accompanying hepatic vein tributaries (experimental study)

Studying Ductular reaction (DR) at early stages after common bile duct ligation (CBDL) in rats we revealed some ductular profiles (DPs) of unusual location - accompanying different caliber tributaries of hepatic veins (THV) including central and sub-lobular venules. We investigated the essence and genesis of these atypically located ductuli. 28 Wistar Rat livers were studied histologically and immunohistochemically in norm and after 6, 12 and 24 hours of CBDL. Biliary system of part of the animals was preliminary injected by Indian Ink. After CBDL the number of DPs including the ones accompanying large and small THV was increased. The diameters of DPs found immediately at central and sublobular veins were varying from 5 to 15 mВµ and of DPs located in the adventitia of the large THV are varying from 10 to 30 mВµ. The cell of these DPs were CK19, CK7 and OV6 positive, but Ki-67 negative, what confirms their belonging to cholangiocytes but denies their proliferative genesis. In the sites of crossing of different size portal tracts (PT) and THV with integration of their connective tissue sheaths were revealed some biliary ducts/ductules dislocated from PT towards the THV and situated within their adventitia. The Indian Ink injected via CBD was found in both - portal and perivenous DPs as well as in bile canaliculi, what confirms their inter-continuity. The biliary ductules dislocated from PT toward THV may accompany hepatic venous pathways reversely up to central venules. These finest ductuli having spare function are likely to communicate with bile canaliculi.