Nadph Oxidase-mediated Reactive Oxygen Species Generated In The Aerobic Exercise On Rat Glial Cell Viability

Excessive Reactive Oxygen Species (ROS) is one of the most important reason of sports fatigue and sports sudden death. Supplement of antioxidants could abate the sports fatigue and sports oxidative damage, for example damage for DNA,protein,fat and other biomacromolecule, which is a hot topic in sports medicine.The traditional point of view consider ROS produced by mitochondria is a kind of toxic material, it's should be eliminated completely.Aerobic exercise is a scientific sports style, it is beneficial for blood vessel of brain and heart.Many people believe that supply the antioxidant after aerobie exercise could eliminate the ROS, and release the "oxidative stress". But the most new reserches of free radical biology indicated that almost all of cells have enzymes, which serve as the function of produce the ROS under the stimulation of cell growth factor and hormones. ROS produced by this way play a vital role in normal cell functions. The inhibition of these enzymes, or ROS was eliminated too much by antioxidants, will result in the cell function lost even death.In the process of sports, accompanied the respiration promotion, cell growth factor and hormone will increase obviously. So if mitochdrial is the exclusive source of ROS? What is the role of other enzymes in ROS incresasing? No researches focus on it until now. Based on the new results of free radical biology, we hyposis that in the sports, the increasing growth factor and hormone activate these enzymes and promote the ROS product, ROS produced by this way play a vital role in cell survival..Nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) mediated generation of reactive oxygen species (ROS) was originally identified as the powerful host defense machinery against microorganism in phagocytes. Recently, some reports indicated that most of non-phagocytic cells also have the NADPH oxidase activity, which is named as phagocyte-like NADPH oxidase, ROS in vivo produced by it act as modulators of cell proliferation, differentiation and other cell functions.Brain consumes about 25% of oxygen. Glial cell is the predominant sort of neurocyte in center nervous system. Glial cell not only supply support, protection, nutrition to neuron, but also play some important roles in nervous system development, nerve impulse transfer, neurocyte rehabilitation, nervous system regeneration.Set up the model of rat aerobic exercise, using primary culture of rat astrocyte as the materials, the goal of this study was to determine whether phagocyte-like NADPH oxidase plays a role in ROS generation and cell survival in rat astrocytes after aerobic exercise. We found that the release of ROS in rat astrocytes was significantly increased after aerobic exercise. Further study indicated that low dose breeding with diphenylene iodonium (DPI) or apocynin (APO), two inhibitors of NADPH oxidase, significantly suppressed ROS release caused by aerobic exercise. Moreover, Cell survival assay showed that DPI, APO, catalase plus superoxide dismutase concentration- and time-dependently decreased the survival of normal astrocytes. Our results suggested that in the aerobic exercise, ROS generation mediated by phagocyte-like NADPH oxidase play a critical role in astrocytes survival. Antioxidants supplement excessively will interfere the normal cell functions even result the cell death in the aeribic exercise.