Enhanced Peribiliary Gland Detachment in Aged Donor Grafts After Rat Liver Transplantation.

Background: Older donor livers have higher rates of biliary complications after transplantation, but early mechanisms of bile duct injury remain incompletely understood. Peribiliary glands (PBGs) in the bile duct wall contain progenitor-like and secretory elements that may support epithelial maintenance and repair. We examined whether donor age is associated with early PBG injury and recovery and explored links with the basement-membrane component laminin. Methods: Livers from young or aged rats were transplanted into young recipients. Extrahepatic bile ducts were evaluated before transplantation and at 24, 72, and 168 h after liver transplantation. PBG morphology and detachment, laminin γ1 expression, and markers related to progenitor-cell characteristics, mucus production, microvascular density, and apoptosis were assessed histologically and immunohistochemically. Results: In aged donor grafts, PBGs showed progressive structural injury after transplantation, with marked cell detachment and loss of glandular architecture at 168 h. In contrast, PBGs in young donor grafts were largely preserved. Areas of PBG cell detachment in aged grafts were spatially associated with reduced laminin γ1 expression. Recovery of laminin γ1 expression over time was less evident in aged grafts and was accompanied by impaired progenitor-cell marker expression, reduced mucus production, persistently decreased microvascular density, and increased shedding of apoptotic PBG cells. Conclusions: Aged donor grafts showed more pronounced early structural PBG injury after transplantation, together with persistent reduction of laminin γ1 expression.