TY - JOUR AU - Oosthuizen , , Jan M.C. AB - 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. KEYWORDS methoxy-indole, N-acetyl-5-methoxy-tryptamine, anti-inflammatory, cyclo-oxygenase inhibitor indomethacin, INTRODUCTION Inflammation is coupled to the production of various mediators at the site of inflammation. These mediators include bradykinin, histamine, acetylcholine as well as prostaglandins. The immune response involves a complex series of cellular events each of which is initiated by antigen-specific and -nonspecific stimuli /I/. One of the antigen-nonspecific TI - Melatonin Levels are Decreased in Rheumatoid Arthritis JO - Journal of Basic & Clinical Physiology & Pharmacology DO - 10.1515/JBCPP.1992.3.1.33 DA - 1992-01-01 UR - https://www.deepdyve.com/lp/de-gruyter/melatonin-levels-are-decreased-in-rheumatoid-arthritis-7iXSC4xo4V SP - 33 VL - 3 IS - 1 DP - DeepDyve ER -