Ultrastructural studies of the bile duct in alcoholic liver disease.

The fine structural characteristics of the bile duct in patients with alcoholic disease are described. Dark cell metamorphosis, edematous microvilli, and increased number of pinocytotic vesicles on the basal wall surface of the duct epithelium were observed. These alterations may be interpreted as evidence of disordered water metabolism, probably reflecting secretion and reabsorption hyperfunction in the duct epithelium. In addition, widened intercellular spaces in the basal half of the epithelium suggested retention of fluid following reverse pinocytosis along the lateral cell surface. Although no alterations of the duct epithelium distinct from those in patients with other liver diseases were apparent in patients with alcoholic liver disease, the basement membrane of the bile duct exhibited unusual duplication with multiple layers and occasional loop-formation in lacunae on the basal surface.