These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Platelet serotonin transporter in patients with diarrhea-predominant irritable bowel syndrome both before and after treatment with alosetron.
    Author: Bellini M, Rappelli L, Blandizzi C, Costa F, Stasi C, Colucci R, Giannaccini G, Marazziti D, Betti L, Baroni S, Mumolo MG, Marchi S, Del Tacca M.
    Journal: Am J Gastroenterol; 2003 Dec; 98(12):2705-11. PubMed ID: 14687821.
    Abstract:
    OBJECTIVES: Serotonin reuptake is mediated by a transporter protein (SERT), and its dysfunctions can alter serotonergic transmission. The present study examines the binding profile of platelet SERT in healthy volunteers as well as in patients with diarrhea-predominant irritable bowel syndrome (D-IBS), both before and after treatment with the 5-HT(3) receptor antagonist alosetron. METHODS: Binding of [(3)H]paroxetine to SERT was assayed in platelet membranes collected from D-IBS patients (12 women, age 21-73 yr) and healthy volunteers (12 women, age 24-68 yr). Both maximal binding capacity (B(max)) and dissociation constant (K(d)) were estimated. In D-IBS patients, binding parameters and symptom severity score were evaluated at baseline and after treatment with alosetron (1 mg b.i.d. for 8 wk). RESULTS: At baseline, B(max) and K(d) values of [(3)H]paroxetine binding were respectively lower and higher in D-IBS patients than in healthy volunteers (B(max): 518.7 +/- 155.9 vs 1151.9 +/- 187.4 fmol/mg, p < 0.001; K(d): 0.19 +/- 0.05 vs 0.06 +/- 0.02 nmol/L, p < 0.001). Symptom severity score in D-IBS patients (50.9 +/- 18.8) was negatively correlated with B(max) (r = -0.964; p < 0.001) but not K(d) values (r = -0.164; p = 0.609). After treatment with alosetron, symptom severity score decreased significantly (14.4 +/- 3.7; p < 0.001), whereas B(max) (522.7 +/- 39.7 fmol/mg) and K(d) values (0.17 +/- 0.07 nmol/L) did not change. CONCLUSIONS: The present results indicate that SERT expressed on platelet membranes of D-IBS patients is characterized by low density and binding affinity and suggest a possible correlation between the reduced capacity of serotonin reuptake and the severity of D-IBS symptoms.
    [Abstract] [Full Text] [Related] [New Search]