Investigations on the Reaction of Metals with Collagen in vivo

After dosing rats with gold thiosulphate a hardening of the collagen can be observed that is attributed to cross‐linkage of the fibrils by the gold ion. Initially no reaction takes place between gold thiosulphate and collagen in vitro. Only after the central gold ion is set free by oxidative destruction of the thiosulphate groups can it enter into a coordination complex with the side‐chain groups, forming new intermolecular bonds. In vivo the gold complex is apparently first taken up into the fibril by virtue of electrostatic forces. In a second slower reaction the thiosulphate groups are displaced by the side chain groups resulting in the cross‐linkage.