Abstract 21076: Exercise Atenuattes the Inflammatory Cytokine Production After Sympathetic Stimulus in Rats
Background: Pronounced activation of the sympathetic nervous system in heart failure (HF) is inversely correlated with survival. Sustained β-adrenoreceptor activation promotes cardiac hypertrophy and cellular injury. Our objective is to evaluate whether previous exercise training is able to reduce the intense inflammatory cytokine production induced by β-adrenergic hyperactivity.
Methods: Male Wistar rats were randomized into four groups (n=8 per group): sedentary non-treated control (C), sedentary treated with isoproterenol 0.3 mg/kg/day administered subcutaneously for 8 days (I), exercised non-treated (E) and exercised plus isoproterenol administered during the last eight days of exercise (EI). Exercised animals ran on a treadmill for 1 h daily 6 times a week for 13 weeks. Cytokine expression was quantified through quantitative RT-PCR and Western Blotting. Cytokine local expression was also verified through immunohistochemistry.
Results: There was no difference in pro-inflammatory cytokine content between E vs C group. However, in EI there was lower gene expression of TNF-alpha (C: 0,3±0.03; I: 0,82±0,09; E: 0,24±0,06; EI: 0,37±0,02; u.a.), IL-6 (C: 0,27±0,03; I: 1,59±0,19; E: 0,25±0,06; EI: 0,3±0,05) and IL-1β (C: 0,3±0,02; I: 1,44±0,13; E: 0,3±0,02; EI: 0,49±0,05). Exercise training diminished TGF-β1 (C: 0,04±0,01; I: 0,63±0,04; E: 0,07±0,01; EI: 0,18±0,03). Exercise training did also affect translational level of cytokine expression: TNF-α (C: 1,03±0,03; I: 3,19±0,09; E: 1,04±0,24; EI: 1,5±0,07; u.a.); IL-6 (C: 1,06±0,11; Iso: 1,51±0,09; Ex: 0,68±0,07; EI: 0,90±0,13). Considering the anti-inflammatory cytokine IL-10, there was higher expression of the cytokine in exercised groups at the transcriptional level (C: 0,10±0,01; I: 0,10±0,02; E: 0,15±0,01; EI: 0,23±0,01) and at transdutional level (C: 1±0,12; I: 0,91±0,08; E: 1,47±0,13; EI: 1,05±0,1). High local positivity of TNF-alpha was verified in regions with intense inflammatory infiltrate and in more preserved regions of I group, but not in the other groups.
Conclusion: Our findings show that previous exercise training induces a cardioprotective profile of inflammatory cytokine production in rats submitted to sympathetic stimulus with isoproterenol.
- © 2010 by American Heart Association, Inc.