Metabolism and characterisation of kinins and Hoe 140 (kinin antagonist) in the synovial fluid of patients with inflammatory joint diseases.

Methods have been optimised for the collection of synovial fluid and the chromatographic separation of individual kinins (bradykinin and kallidin) in the fluid by HPLC. In addition, the stability of the kinin antagonist, Hoe 140, in synovial fluid was compared with that of synthetic bradykinin. Although bradykinin was completely degraded after incubation for only 6 h in pooled synovial fluid obtained from patients with rheumatoid arthritis, Hoe 140 was stable for as long as 2 weeks under the same conditions. These studies will provide quantitative information regarding levels of kinins in inflamed joints and an insight into the therapeutic potential of kinin antagonists.