Some Factors Involved in the Fibrogenesis of Collagen in vitro ∗

Summary

1. A variety of organic substances derived from animal and plant sources can induce the precipitation of collagen- and long-spacing-type fibrils from acid extracts of ichthyocol in a manner similar to that of serum glycoprotein. These fibril-precipitating agents appear to be thermostable and are not altered by subsequent exposure to 20% trichloracetic acid. 2. Hyaluronate, chondroitin sulfate and heparin produce fibrous precipitates directly on addition to ichthyocol filtrates. At low ionic strength these fibrils are unstriated. At ionic strengths of 0.1 to 0.2 (NaCl) some long-spacing-type fibrils are formed but collagen-type fibrils have not been observed. 3. The components necessary for the formation of cross-striated fibrils appear to be contained in the fibrous material extracted from the connective tissue; the action of the precipitating substances seems to be relatively non-specific under the conditions of these experiments.