Melatonin in rheumatoid arthritis: synovial macrophages show melatonin receptors.
The pineal neurohormone melatonin is widely recognized as exerting important immunoenhancing effects that act on specific receptors in immunocompetent cells. This action results in stimulation of cytokine production in lymphocytes and macrophages. Here we report that the nocturnal plasma concentration of melatonin in rheumatoid arthritis (RA) patients is higher than in healthy controls. Furthermore, melatonin is present in the synovial fluid of RA patients and synovial macrophages express a specific binding site. We suggest that melatonin may exert a disease-promoting role in RA.
Centre for Experimental Pathology, Istituto Cantonale di Patologia, Locarno, Switzerland. georges.maestroni@ti.ch
Georges J M
GJ
Maestroni
Alberto
A
Sulli
Carmen
C
Pizzorni
Barbara
B
Villaggio
Maurizio
M
Cutolo
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D001327:Autoimmune Diseases / Q000503:physiopathology*; D002940:Circadian Rhythm; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000502:physiology*; D008875:Middle Aged; D015213:Neuroimmunomodulation / Q000502:physiology*; D009928:Organ Specificity; D010870:Pineal Gland / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000032:analysis / Q000502:physiology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000032:analysis / Q000502:physiology*; D044094:Receptors, Melatonin; D013582:Synovial Fluid / Q000737:chemistry* / Q000166:cytology; D013583:Synovial Membrane / Q000378:metabolism
D016207:Cytokines; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D044094:Receptors, Melatonin; D008550:Melatonin