[Peptidyl prolyl hydroxylase activity in relation to the actual collagen biosynthesis in cotton pellet granuloma of guinea pig (author's transl)].

During the different stages of granuloma formation peptidyl prolyl hydroxylase activity and neutral salt soluble collagen were determined in the granuloma tissue. In parallel peptidyl prolyl hydroxylase activity, "collagen-like protein", and free hydroxyproline were measured in the serum of the same animals at correspondant time distances. A close correlation was found between the enzyme activity and the other parameters of collagen synthesis. These results confirm the conclusion that hydroxylation of polypeptide may be a rate limiting step in collagen biosynthesis. In addition the investigations revealed a close correlation between enzyme activity in the tissue and enzyme activity in the serum.