[The synovial membrane in rheumatoid arthritis: change in the glycosaminoglycan pattern]

For examination of glycosaminoglycane (GAG) in the normal synovial membrane and in the synovial membrane of patients with rheumatoid arthritis (RA) fat free dry tissue was digested with papain. The GAG was fractonated with cetylpyridiniumchloride according to Svejcar's and Robertson's techniques and afterwards it was characterised in detail. The total amount of GAG per gramme of fat free dry tissue was the same in RA and in controls. The GAG distribution pattern was significantly changed: 1. A large fraction of hyaluronic acid was found in acutely inflamed tissue with only few scars. 2. In tissue with much cicatrization, however, acute processes accompanied by large amounts of hyaluronic acid appeared unimportant. There the L-iduronic acid content of the Ch-4-S and the Ch-6-S fractions (increased hybridization) and its total amount was increased. The tendency to increased epimerization of D-glycuronic acid to L-iduronic acid in the GAG-chains was clearly shown by an increase of the GAG-fraction, which contains relatively pure dermatane sulphate.