Open AccessSubstance p and arthritis: analysis of plasma and synovial fluid levels
Author(s) -
Wayne Marshall K.,
Chiu Basil,
Inman Robert D.
Publication year - 1990
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780330111
Subject(s) - synovial fluid , substance p , osteoarthritis , rheumatoid arthritis , medicine , arthritis , radioimmunoassay , inflammatory arthritis , peripheral , endocrinology , pathology , gastroenterology , neuropeptide , receptor , alternative medicine
The uncadecapeptide substance P (SP), which is localized in peripheral and central terminals of afferent nerve fibers with polymodal nociceptors, has recently been implicated as having a neurogenic, inflammatory role in experimental arthritis. We used a radioimmunoassay to measure SP levels in plasma and synovial fluid samples from patients with rheumatoid arthritis (RA), osteoarthritis (OA), Reiter's syndrome (RS), and posttraumatic arthritis, as well as in plasma samples from 13 normal subjects. Plasma SP levels in RS patients exceeded levels in RA and OA patients, which in turn exceeded levels in posttrauma patients and in normal subjects. Synovial fluid SP levels exceeded respective plasma levels for all groups, except in RS patients, in whom the plasma level was not significantly different from that in synovial fluid. SP levels in synovial fluid of RA, OA, and RS patients did not differ significantly from each other, but the level in posttrauma patients was higher than in all other groups (P > 0.005). These studies demonstrate localized intraarticular SP release, and significant plasma/synovial fluid SP concentration gradients in several forms of arthritis.