[Investigations on protein metabolism in malleus and incus (author's transl)]

Protein and mucopolysaccharide metabolism was studied in the auditory ossicles of rabbits after administration of tritiated amino acids to three and of S35 to two animals. No differences between S35 and aminoacid turnover was seen, indicating a parallelmetabolism of proteins and mucopolysaccharides of the intercellular substance. The tissue, cartilage and bone, shows a metabolism on the molecular level. Areas of cartilage ground substance adjacent to the incudomalleolar joint and the interglobular spaces are not labelled by the radioactive substances. They are excluded from metabolical turnover, while the adjacent cells remain vital. This observation indicates a change of cellular properties, from cartilage to bone cell. The subperiostal bone has lower metabolism than the underlying skeinlike bone. Few osteones were found.