The aim of this study was to investigate if a pre-exercise alkalosis-mediated attenuation of HSP72 had any effect on the response of the same stress protein after a subsequent exercise. Seven physically active males [25.0 ± 6.5 years, 182.1 ± 6.0 cm, 74.0 ± 8.3 kg, peak aerobic power (PPO) 316 ± 46 W] performed a repeated sprint exercise (EXB1) following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Participants then completed a 90-min intermittent cycling protocol (EXB2). Monocyte expressed HSP72 was significantly attenuated after EXB1 in BICARB compared to PLAC, however, there was no difference in the HSP72 response to the subsequent EXB2 between conditions. Furthermore there was no difference between conditions for measures of oxidative stress (protein carbonyl and HSP32). These findings confirm the sensitivity of the HSP72 response to exercise-induced changes in acid-base status in vivo, but suggest that the attenuated response has little effect upon subsequent stress in the same day.
Keywords: Alkalosis; Bicarbonate; HSP72; Monocyte; Stress.