Abstract
Fresh synovial tissue was taken from two normal subjects and five patients with rheumatoid arthritis, and treated so that catecholaminergic sympathetic nerve fibres could be seen. A fluorescent network of varicose fibres was visible in normal as well as in rheumatoid synovial tissue. In the rheumatoid inflammatory tissue an increased number of fluorescent sympathetic nerve fibres could be seen in close proximity to blood vessels, even in the smallest synovial plica, indicating that the proliferation of inflammatory vessels is accompanied by simultaneous sympathetic nerve proliferation. A nervous component might thus contribute to the inflammatory process in human rheumatoid arthritis.