Effect of Exercise Combined with Hypoxia on Neutrophil Bactericidal Activity and Lymphocyte Apoptosis

The main rationale for the clinical use of hypoxic intervention concerns the potential cross-protective value of adaptation to one stress, which then provides resistance to another stress. Furthermore, acclimatization to long-term hypoxia includes a progressive increase in pulmonary ventilation, adaptation of cardiovascular and haematopoetic systems, and alteration at the tissue level to optimize oxygen utilization, thereby improving aerobic capacity and resistance to acute hypoxic stress. The increases in both the stress resistance and the oxygen delivery/utilization by hypoxic intervention have been suggested to improve exercise performance and be of value in the prevention and treatment of various illness. Contrarily, the long-term consequence of hypoxia may also have detrimental effects, including distubrance of circulatory redox status and dyregulation of vascular tone and thrombo-inflammation due to the cumulative effects of persistent bouts of hypoxia. The beneficial or detrimental effects of hypoxic intervention may vary substantially with the concentration of air O2 exposure and the subsequent change in the circulatory redox status under the hypoxic regimen. However, the effects of exercise combined with hypoxia on the innate/adaptive imunne responses remain unclear. Therefore, the purpose of this study is to clarify the relationships between hypoxic exercise training and innate/adaptive imunne functions to provide a “safe” and “effective” strategy of rehabilitation medicine to improve aerobic fitness and increase resistance to pathogen infection, consequently promoting health in individuals. Blood neutrophil plays an important role in the immune system, forming the first defense against invading microorganisms by phagocytosis and oxidative burst. Subsequently, phagocytic neutrophils are also themseveles ingested by macrophages before they disintegrate. Although exercise or hypoxia intervention was observed to modulate blood nurophile activity in an intensity manner, effects of acute/chronic exercise combined with hypoxia on elimination of pathogen by neutrophil remains unclear. Intracellular redox status plays an important role in process of programmed cell death. Strenuous exercise may also manifest an imbalance between reactive oxygen species and antioxidant defense, resulting in an oxidative stressful environment in the body. Our previous study indicated that severe exercise decreases lymphocyte reduced glutathione content, in turn accelerating oxidative stress-induced apoptotic process. However, moderate exercise attenuates lymphocyte apoptosis induced by oxidative stress via improving intracellular anti-oxidative capacity. Acute hypoxic is associated with concentration, mode, or duration-dependent immune response, which may be similar to the exercise response. Therefore, this study will clarify the relationships between acute/chronic exercise combined with hypoxia and lymphocyte apoptosis to prevent individuals from acquired immune deficient when undergoes hypoxic exercise. Accordingly, we will conduct this three-year study that includes 1st year study: acute exercise, acute hypoxia, acute exercise combined with hypoxia; 2nd year: various long-term intermittent hypoxic interventions; and 3rd year study: various long-term hypoxic exercise interventions to clarify how the acute/chronic exercise combined with hypoxic interventions affect innate (i.e., blood complement activation, as well as, neutrophil phagocytosis/oxidative burst, complement receptor/ adhesion molecule expressions, and subsequent apoptosis) and adaptive (i.e., lymphocyte phenotypes, re-distribution, naïve/memory, activate status, aging/senescence, apoptotic pathways and mechanisms) immune responses. We expect that these results from this study can aid in determining appropriate hypoxic exercise intervention (as a new strategy of rehabilitation combined with environment factor) to promot health and improve physical fitness in individuals.

Project ID:PC9902-0202
External Project ID:NSC97-2314-B182-003-MY3