title: [Role of opioid peptide in rheumatoid arthritis--detection of beta-endorphin in synovial tissue].
abstract: The presence of beta-endorphin (beta-end) was immunohistologically identified in synovial tissue samples biopsied from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). The amount of beta-end in culture supernatants of synovial tissue explants was also determined by RIA. beta-end was strongly detected in mainly superficial synovial cells, vascular endothelial cells and a few synovial interstitial cells in RA patients, but not in OA patients. In RA patients the beta-end concentration was significantly higher in the supernatants of tissue explants (26.4 +/- 8.3 pg/ml) than in the plasma of the same patients (15.3 +/- 2.5 pg/ml) (p < 0.01). Using isolated synovial cells, the beta-end concentration in the culture supernatants of non-adherent cells (19.4 pg/ml) was higher than that of adherent cells (4.0 pg/ml). It is suggested that beta-end is produced by non-adherent cells such as lymphocytes and neutrophils in addition to synovial lining cells and endothelial cells and may play some role in the pathology of RA synovial inflammation.
authors.affiliation: Department of Rheumatology, Dai-ichi Hospital, Nippon Medical School.
authors.forename: M
authors.initials: M
authors.lastname: Koiwa
authors.forename: H
authors.initials: H
authors.lastname: Shiga
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Yoshino
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D004723:Endorphins / Q000502:physiology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism; D013583:Synovial Membrane / Q000737:chemistry*; D001615:beta-Endorphin / Q000032:analysis*
chemical_list: D004723:Endorphins; D001615:beta-Endorphin