Hypoxic Exercise Training Suppresses Oxidative Stress‐induced Lymphocyte Apoptosis

Abstract

This study investigates how hypoxic exercise training affects oxidative stress‐induced lymphocyte apoptosis and further explores its underlying mechanisms. Twelve sedentary males were trained on a bicycle ergometer at about 60%VO2max under 15% O2 air condition for 20 minutes per day, 5 days per week for 4 weeks. Sublethal oxidative stress was administered by treating the lymphocytes with 200μM H2O2, to closely approximate in vivo pro‐oxidative conditions. Our results demonstrated that before the training, strenuous exercise enhanced H2O2‐induced phosphotidyl serine exposure of lymphocyte, which was accompanied by a decline in mitochondrial transmembrane potential (MTP) and increases in active‐form caspase 3, 8 and 9 contents in lymphocyte. However, 4 weeks of hypoxic exercise training attenuated H2O2‐induced lymphocyte caspase activation and apoptotic response during strenuous exercise. We conclude that although strenuous exercise can promote oxidative stress‐induced lymphocyte apoptosis by declining MTP and activating intrinsic and extrinsic caspases, long‐term hypoxic exercise training suppresses the acute exercise effect on oxidative stress‐induced lymphocyte apoptosis.