title: Melatonin levels are decreased in rheumatoid arthritis.
abstract: The hormone, melatonin, is a product of the pineal gland. This methoxy-indole, also known as N-acetyl-5-methoxy-tryptamine, is structurally related to indomethacin, a derivative of methylated indole. The fact that indomethacin has been used successfully in patients suffering from certain chronic inflammatory conditions (such as rheumatoid- and osteoarthritis) gives rise to the question as to whether melatonin also possesses anti-inflammatory virtues. This hypothesis has been tested by determining melatonin concentration levels by means of a radioimmunoassay in patients with rheumatoid arthritis. The daytime melatonin levels of untreated patients were significantly lower (mean concentration = 5.76 pg/ml) than the normal value (mean concentration = 15-33 pg/ml). The second part of this study showed that the administration of indomethacin (100 mg/day) to normal healthy subjects led to a 14.7 pg/ml decrease in plasma melatonin levels. This may indicate that melatonin and indomethacin act synergistically.
authors.affiliation: Department of Medical Physiology and Biochemistry, Faculty of Medicine, University of Stellenbosch, Republic of South Africa.
authors.forename: S K
authors.initials: SK
authors.lastname: West
authors.forename: J M
authors.initials: JM
authors.lastname: Oosthuizen
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D008550:Melatonin / Q000097:blood*; D008593:Menopause; D008875:Middle Aged; D011863:Radioimmunoassay
chemical_list: D008550:Melatonin; D007213:Indomethacin