TITLE:
Effects of Exercise Intensity on Peripheral Oxidative Stress and Brain 3-Nitrotyrosine and Brain-Derived Neurotrophic Factor Levels in Rats
AUTHORS:
Yoichi Ohno
KEYWORDS:
Oxidative Stress, 3-Nitrotyrosine, Brain-Derived Neurotrophic Factor, Exercise Intensity
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.16 No.8,
September
1,
2026
ABSTRACT: Oxidative stress plays an important role in both physiological adaptation and the development of various diseases, and exercise intensity is considered a key factor influencing oxidative and neuronal responses. This study investigated the effects of different exercise intensities on peripheral oxidative stress and neuronal factors in the central nervous system. Twelve 8-week-old male Wistar rats were randomly assigned to three groups (n = 4 each): control (CON), moderate-intensity exercise (MOD), and high-intensity exercise (HIGH). Rats in the MOD and HIGH groups performed treadmill running five times per week for 8 weeks at speeds of 15 and 25 m/min, respectively. Blood levels of reactive oxygen metabolites-derived compounds (d-ROMs), biological antioxidant potential (BAP), and the BAP/d-ROMs ratio were measured before the intervention and at Week 4 and Week 8. After the intervention, the frontal cortex, hippocampus, and striatum were collected, and 3-nitrotyrosine (3-NT) and brain-derived neurotrophic factor (BDNF) levels were determined using ELISA. At Week 8, d-ROM levels were significantly higher in the HIGH group than in the CON group. In contrast, BAP levels were significantly lower in the HIGH group than in the MOD group, and the BAP/d-ROMs ratio was significantly lower in the HIGH group than in the CON group. Hippocampal 3-NT levels were significantly lower in the HIGH group than in the MOD group, whereas no significant pairwise differences were observed in the frontal cortex or striatum. BDNF levels in the frontal cortex, hippocampus, and striatum were significantly lower in the HIGH group than in the CON group. These findings indicate that exercise intensity differentially affects oxidative stress and neuronal factors. In particular, prolonged high-intensity exercise was associated with increased peripheral oxidative stress, reduced antioxidant capacity and impaired redox balance, and region-specific alterations in brain 3-NT and BDNF levels. These results suggest that exercise intensity influences physiological responses in both peripheral and central tissues and should be carefully considered when designing exercise interventions.