(Forts.)
The nociceptive response (licking of the injected paw) was significantly reduced from 25 micrograms (-59 +/- 11%) in the early phase, whereas the lowest active dose in the late phase was 50 micrograms (-46 +/- 17%). For both phases, a total inhibition was obtained with 100 micrograms. It is concluded that the effect of 5-HT on pain tests may differ according to the applied stimulus and the parameter assessed; unspecific effects of 5-HT may modify motor reactions to noxious stimuli. Mechanical test (assessment of vocalization) was the most sensitive to 5-HT. These observations are of importance in order to further study the pharmacological mechanisms involved in 5-HT spinally induced antinociception.
Department of Clinical Oral Physiology, Center for Clinical Oral Science, Karolinska Institutet, Huddinge, Sweden. per.alstergren:ofa.ki.se
Pain and synovial fluid concentration of serotonin in arthritic temporomandibular joints.
Pain. 72(1-2):137-43, 1997 Aug.
Abstract:
The aim of this study was to investigate the relation between
serotonin in the synovial fluid (SF-5-HT) and pain of arthritic temporomandibular joints (TMJ). The study comprised 1 male and 10 female patients (22 TM joints) with bilateral TMJ pain or tenderness and a mean age of 42 years. The patients were studied regarding pain from the TMJ at rest and during mandibular movements as well as regarding pressure pain thresholds and tolerance levels over the TMJ. TMJ samples, obtained by saline washing of the joint, and blood serum samples were taken for measurement of the 5-HT content. There was a positive correlation between SF-5-HT and pain in the TMJ upon movement. Maximum voluntary mouth opening ability was negatively correlated to SF-5-HT. In conclusion, the results of this study indicate that 5-HT in the TMJ synovial fluid is related to pain perceived upon movement of the joint and to decreased mandibular mobility.
