The Effect of Aerobic Training and Cholecalciferol on IGF-I and IGFBP-3 in the Bone Tissue of Rats Poisoned with Hydrogen Peroxide

 Exercise and vitamin D can improve bone density by reducing bone loss. Growth factors such as IGF-I and IGFBP-3 are appeared to increase bone turnover in response to mechanical load, and free radicals attenuate the release of these growth factors.

 We assessed the effect of concurrent aerobic training and cholecalciferol administration along with hydrogen peroxide injection on the levels of IGF-I and IGFBP-3 expression in the bone tissue of rats.

 Thirty-six adult Wistar rats were randomized into six groups (n = 6), including healthy control, sham, hydrogen peroxide (H2O2), H2O2 + aerobic training, H2O2 + cholecalciferol, and H2O2 + aerobic training + cholecalciferol. The rats were intraperitoneally administered with one mmol/kg. Body weight (BW) of H2O2 three times a week on even days and 0.5 μg/kg.bw of cholecalciferol daily. Aerobic training (at a speed of 4 - 20 m/min, for 20 - 60 minutes) was performed five days/w for eight weeks. The expression of IGF-I and IGFBP-3 was measured by real-time (RT)-PCR. Data were analyzed using the independent t-test, two-way ANOVA (exercise × vitamin D), and Bonferroni’s post-hoc test in SPSS 26 at the significance level of P ≤ 0.05.

 The results showed that H2O2 significantly reduced the gene expressions of IGF-I (P = 0.001) and IGFBP-3 (P = 0.001) in the bone tissue. Also, exercise and vitamin D augmented the expression of IGF-I (P = 0.008) and IGFBP-3 (P = 0.0001) as post-hoc analysis showed that aerobic training had the greatest effect on the expression of IGF-I and IGFBP-3 (P < 0.05). In addition, the amplifying effects of aerobic training and cholecalciferol on the gene expressions of IGF-I and IGFBP-3 were also remarkable (P < 0.1).

 The mechanical load created by aerobic training exerted the greatest augmenting effect on the gene expression of IGF-I and IGFBP-3. Moreover, the interactive effect of aerobic training and cholecalciferol was also significant.