Research article

Alteration of serotonin transporter density and activity in fibromyalgia

Laura Bazzichi¹ , Gino Giannaccini² , Laura Betti² , Giovanni Mascia² , Laura Fabbrini² , Paola Italiani² , Francesca De Feo² , Tiziana Giuliano¹ , Camillo Giacomelli² , Alessandra Rossi² , Antonio Lucacchini² and Stefano Bombardieri¹

¹  Department of Internal Medicine, Division of Rheumatology, University of Pisa, Via Roma 67 - 56126 PISA Italy

²  Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, University of Pisa, Via Bonanno 6, 56126, Pisa, Italy

author email corresponding author email

Arthritis Research & Therapy 2006, 8:R99doi:10.1186/ar1982

Published:	21 June 2006

Abstract

The aim of the study was to evaluate the kinetic parameters of a specific serotonin transporter (SERT) and serotonin uptake in a mentally healthy subset of patients with fibromyalgia. Platelets were obtained from 40 patients and 38 healthy controls. SERT expression and functionality were evaluated through the measurement of [³H]paroxetine binding and the [³H]serotonin uptake itself. The values of maximal membrane binding capacity (B_max) were statistically lower in the patients than in the healthy volunteers, whereas the dissociation constant (K_d) did not show any statistically significant variations. Moreover, a decrease in the maximal uptake rate of SERT (V_max) was demonstrated in the platelets of patients, whereas the Michaelis constant (K_m) did not show any statistically significant variations. Symptom severity score (tiredness, tender points index and Fibromyalgia Impact Questionnaire) were negatively correlated with B_max and with V_max, and positively correlated with K_m. A change in SERT seems to occur in fibromyalgic patients, and it seems to be related to the severity of fibromyalgic symptoms.