Abstract
At one time it was thought that biliary epithelial cells simply formed the lining to the tubular conduits which constitute the biliary tract. Development of in vitro systems for culturing biliary epithelial cells has enabled functional studies which increasingly show that this is far from true, and that biliary epithelial cells do have important functional roles. Disruption of these functions may be involved in the generation of pathology. Most functional studies to date have utilised cells isolated from rat liver. Increasingly, variations are being found between human and animal cells both in terms of function and phenotype. The relevance of animal cells in the study of human disease therefore remains obscure. Human biliary tract disease has to date been studied almost exclusively by examination of histological sections. The development of improved methods for isolating highly pure biliary epithelial cells from human liver provides a new technology with which to investigate directly the dynamics of human biliary epithelial cell biology and pathobiology. It is predicted that further progress will now be made in dissecting the biology and physiology of human biliary epithelium.