SPECIFIC AIMS:
1. To systematically measure for the first time in healthy children and adolescents the effects of brief bouts of exercise on:
1. Numbers of circulating PMBCs, their subsets and key intercellular adhesion molecules (ICAMs).
2. PBMC gene regulation of stress, inflammatory, and growth/repair mediators \[including: interleukin-4 (IL-4), IL-6, IL-10, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma), growth hormone (GH), insulin-like growth factor-I (IGF-I), heat shock proteins (Hsp)\].
3. Circulating (serum) and intracellular PBMC levels of key mediators by flow cytometry and cell culture techniques.
4. Circulating endogenous triggers of PBMC mediator responses-soluble Hsp, IL-6, and F2-isoprostanes.
2. To determine how the acute PBMC responses are altered by gender, pubertal status, body composition (measured by whole-body and regional DEXA), and fitness (measured by progressive cycle ergometry and gas exchange).
3. To determine the relationship in healthy children and adolescents among acute PBMC responses to exercise, biochemical precursors of the metabolic syndrome (insulin, glucose, lipids), and the balance of the TH1/TH2 immune response.
