Ductular Reaction in Total and Partial Biliary Obstruction in Experimental Settings

Abstract

In this paper, the features of ductular reaction (DR) and remodeling of the biliary tract in experimental models are discussed in total and selective biliary occlusion. It has been shown that the intensity of DR, as well as the shape, number, and topography of ductular profiles following common bile duct occlusion (CBDO) are closely related to the duration of the biliary obstruction. In addition, the formation of new ductular profiles can occur by the widening of existing bile ducts/ductules as a result of cholangiocyte proliferation, hepatocyte transdifferentiation, and/or activation and differentiation of stem/progenitor cells. It has been concluded that DR induced by CBDO consists of the components of all types of DRs, including I, II (A and B), and III, thus increasing the interest in further studies of this model. In the DR following CBDO, the consequent "preproliferative" and "proliferative" phases developed in parallel with cells differentiation and transdifferentiation (the "para-proliferative" phase) should be distinguished. The dynamics of these phases are important to consider for further detailed classification of DRs. During selective biliary obstruction, the full range of DR characteristics for CBDO has not been determined (mainly the events of biliary proliferation and fibrosis are noted). However, the great compensatory potential of the biliary bed has been confirmed, as reflected by the formation of new collaterals between congested and noncongested bile ducts.