Biosynthesis of interstitial types of collagen by albumin-producing rat liver parenchymal cell (hepatocyte) clones in culture.

We have analyzed collagenous components produced by an albumin-producing rat liver parenchymal cell clone (BB) in culture. The cells secreted over 90% of the [3H]proline-labeled collagenous components into the medium after 18 h of incubation in vitro. Analysis of the components by sodium dodecyl sulfate-polyacrylamide gell electrophoresis and by carboxymethylcellulose chromatography of cyanogen bromide peptides after separation of individual collagen chains showed that the cells produced type I, type I trimer, and type II collagens in the ration 59:29:4. These components account for over 90% of the collagen isolated. Type I and type I trimer collagens were present in both the medium and cell layer fractions, but type III collagen was found solely in the medium. The cells also produced other minor collagenous components, one of which was quite similar to type V collagen. Analysis of collagen components produced by another liver parenchymal cell clone (BC) and by three subclones derived from BB cells showed that these cloned cells synthesized similar types of collagen. These results support the idea that parenchymal cells play an essential role in the heaptic connective tissue metabolism under normal and pathological conditions.