Light microscopic distinction of collagens in hepatic cirrhosis.

Histochemical studies by Sesta et al. (1965) demonstrated in hepatic cirrhosis an embryonic-type collagen that differs from reticulum fibers. Grimaud and coworkers observed type IV collagen in cirrhotic lesions. To determine whether or not this collagen can be visualized by light microscopy, sections fixed in Carnoy-type solutions were treated with the periodic acid -Na bisulfite - resorcin-fuchsin (PBRF) reaction for basement membranes. Reticulum and coarse (Type I) collagen fibers were visualized with picro-Sirius Red F3BA. In normal livers, basement membranes occurred only around bile ducts and blood vessels. In hepatic cirrhosis basement membrane-like material extended from septa into nodules. The reaction patterns were similar to immunofluorescence pictures of Type IV collagen. The ratios of different collagens varied widely and were apparently determined by type and of lesions and other factors. For further studies, improved light microscopic reactions are needed, especially for simultaneous demonstration of embryonic and basement membrane-type collagens in contrasting colors.