Electron transporting enzymes of rheumatoid connective tissue.

The oxidative enzyme system of the synovial membrane and rheumatoid node from rheumatoid arthritic patients has been studied by histochemical and biochemical methods. As compared to the control synovial membranes, succinic dehydrogenase activity was substantially higher in the rheumatoid arthritic synovial membranes, and was still higher in the rheumatoid nodes, in which only the cells forming the palisade had succinic dehydrogenase activity. As compared to the controls, in response to menadione succinic dehydrogenase was significantly activated. The reducible ubiquinone content of the rheumatoid synovial membrane and the rheumatoid node was by several orders of magnitude higher than in the controls.