Extrahepatic cholestasis causes excessive extracellular matrix formation perisinusoidally. Ito cells, transitional and endothelial cells are considered to be a source of
extracellular matrix proteins in experimental
cholestasis. The localization of
collagens type III and type IV in human liver in
extrahepatic cholestasis was investigated immunohistochemically in the present study. Immersion fixation was used after modification to be applied to surgical biopsies with commercially available kits. Sinusoidal changes were observed that indicated excessive
collagen and matrix formation. Light microscopically, increased immunostaining with the two
collagen antibodies was found perisinusoidally and portally. Ultrastructurally,
collagen type III positive fibres were found beneath basement membranes of vessels, in
collagen bundles and as a fibrillar network in the space of Disse.
Collagen type IV immunostaining was located in portal tracts and near hepatocyte microvilli. Intracellular staining with
collagen type IV was detected in the rough endoplasmic reticulum of some transitional cells. Immunostaining was located around transitional cells, Ito cells or endothelial cells mainly. Our study indicates that Ito cells, transitional and endothelial cells are the main source of
collagens type III and IV in the space of Disse in
extrahepatic cholestasis in humans.