Caloric restriction suppresses exercise-induced hippocampal BDNF expression in young male rats

Abstract

Both exercise training and chronic caloric restriction contribute to brain health through enhanced expression of brain-derived neurotrophic factor (BDNF). This study investigated the synergistic effects between 12-week low-intensity exercise training and caloric restriction on hippocampal BDNF expression with redox status in rats. Twenty-six, 7-week-old male Wistar rats were randomly divided into the following 4 groups: (1) sedentary control (Con, n = 7), (2) exercise (Ex, n = 6), (3) caloric restriction (CR, n = 7), and (4) caloric restriction and exercise training (ExCR, n = 6). Although Con and Ex rats were fed ad libitum over time, CR and ExCR rats consumed 40% less food compared to Con rats. Ex and ExCR rats underwent low-intensity treadmill running (30 min/day, 5 days/week). Forty-eight hours after the termination of the 12-week intervention, rats were sacrificed and the hippocampus was quickly dissected for measuring BDNF expression and markers of oxidative stress, including 4-hydroxy-2-nonenal (4-HNE). Hippocampal BDNF expression was significantly increased in Ex compared to Con rats (p = 0.007), whereas the exercise-induced increase in BDNF was completely suppressed by a combination with caloric restriction. Furthermore, we observed a significant relationship between hippocampal BDNF and 4-HNE expression (r = 0.725, p < 0.001). Our findings indicate that exercise training combined with caloric restriction might not have a synergistic effect on hippocampal BDNF expression in young rats. Moreover, exercise-induced oxidative stress can trigger BDNF expression in the hippocampus.

Keywords

• exercise
• diet
• combined effect
• brain-derived neurotrophic factor
• 4-hydroxy-2-nonenal