Conference presentation
Endurance-training effects on intracellular calcium andiron in CD4+ lymphocytes in young and old men
60th ACSM Annual Meeting and 4th World Congress on Exercise is Medicine (Indianapolis, Indiana, 28 May - 1 June)
2013
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Abstract
<p><p id="x-x-x-P11">Regular exercise is thought to maintain or improve the adaptive immune (lymphocyte) response but there is little data on the long-term exercise effects on CD4<sup>+</sup> activation in young and older individuals. <p id="x-x-x-P12"><strong>PURPOSE:</strong> To investigate if 12 months of aerobic/endurance training would enhance CD4<sup>+</sup> activation via increased CD25 receptor expression and density in trained older and young men compared to sedentary controls. <p id="x-x-x-P13"><strong>METHODS:</strong> We compared young (30±5 yr) trained (TRY, n = 14) and sedentary (UTY, n = 12) men to older (69±5 yr) trained (TRO, n = 14) and sedentary (UTO, n = 10) men for 12 months. Older men cycled for three 50 min sessions per week (60-70% VO<sub>2peak</sub>) while the TRY group completed daily endurance training (90-120 min per day, 60-80% VO<sub>2peak</sub>). Venous blood was analysed every month for resting lymphocyte count and CD4<sup>+</sup>CD25<sup>+</sup> expression and density by flow cytometry. Results were analysed by repeated measures two-way ANOVA (time vs group) with Bonferroni <strong>post hoc</strong> test (between-group and between-month), with p<0.05. <p id="x-x-x-P14"><strong>RESULTS:</strong> The TRY group had a significantly higher concentration of CD4<sup>+</sup> than the UTY for 4 months (37±7%); there was no difference in lymphocyte count between TRO and UTO. The TRO group had a significantly greater percentage of CD4<sup>+</sup>CD25<sup>+</sup> than the UTO group (39±16%) for 8 months, and TRY (52±20%) and UTY (57±19%) groups for 6 months. The TRO, TRY and UTY groups showed a significantly different % of CD4<sup>+</sup>CD25<sup>+</sup> compared to the previous month in April, May, October and November. CD25 density was significantly greater in the TRY compared to UTY group (34±11%) for 10 months, and in TRY compared to TRO (39±13%) and UTO (44±12%) groups for 10 months. CD25 density was significantly different to the previous month for TRY and UTY in April, May, July, August, September, October; for TRO and UTO, in February, September. <p id="x-x-x-P15"><strong>CONCLUSION:</strong> Moderate intensity/duration endurance training increased the percentage of CD4<sup>+</sup> expressing CD25<sup>+</sup> in older men, possibly by increasing memory cells. Endurance training in young athletes increased CD4+CD25+ density rather than the number/percentage of lymphocytes positive for the receptor. Exercise may increase the CD4<sup>+</sup> response through different mechanisms depending upon age. Furthermore, there are seasonal differences in CD4<sup>+</sup>CD25<sup>+</sup> expression which may affect adaptive immunity.</p>
Details
- Title
- Endurance-training effects on intracellular calcium andiron in CD4+ lymphocytes in young and old men
- Creators
- Suzanne Broadbent - Southern Cross University
- Conference
- 60th ACSM Annual Meeting and 4th World Congress on Exercise is Medicine (Indianapolis, Indiana, 28 May - 1 June)
- Identifiers
- 2511; 991012821401002368
- Academic Unit
- School of Health and Human Sciences
- Resource Type
- Conference presentation