The Effects of Stress and Serotonin System on Th Cell Activity

Abstract

Aim: Stress, has varying effects on the immune system. Serotonin has important effects on both the stress response and the immune system. The aim of this study was to investigate the role of serotonin in the effects of acute stress on T helper cell activity. Methods: 54 rats allocated into groups; Control (C), Methiothepin (M), Ondansetron (O), Acute stress (AS), AS+M, AS+O. After the completion of cold-immobilization stress protocol rats were exsanguinated, whole blood count recorded, plasma serotonin, IL-6, IL-17 and IL-25 levels were determined. Our data evaluated with non-parametric multiple comparison tests by using STAT/Statistic program. Project was approved by Local Ethics Committee for Animal Experiments of Gazi University. Results: While acute stress significantly decreased leukocyte count (p=0.02) and IL-17 (p=0.002), IL-6 and IL-25 levels were not changed. Both ondansetron and methiothepin lowered IL-17 levels (p<0.05), but only methiothepin effected IL-17 levels under acute stress (p=0.01). Conclusion: The decrease in leukocyte counts shows that stress protocol effected immune system. The return of IL-17 levels to the control levels by methiothepin suggests that the serotoninergic system uses 5HT-1A, 5HT-1B and / or 5HT-7 receptors for the suppression of Th17 activity under acute stress.