The effect of vitamin D supplementation and high-intensity interval training on BDNF-TrkB expression in rats fed a high-fat and high-carbohydrate diet

Introduction: Brain-derived neurotrophic factor (BDNF) has beneficial effects on non-neuronal tissues, particularly cardiovascular cells, but its effects on the BDNF-TrkB pathway in heart tissue have not been studied. Therefore, the aim of the study was to investigate the effect of high-intensity interval training (HIIT) and vitamin D supplementation (VitD) on the protein levels of cardiac BDNF-TrkB in rats fed with a high-fat and high-carbohydrate diet. Materials & Methods: Sprague Dawley rats were divided into normal diet (ND), high fat and high carbohydrate (HFD+HC), high fat and high carbohydrate with HIIT (HFD+HC+HIIT), high fat and high carbohydrate with VitD (HFD+HC+VitD), and high fat and high carbohydrate with HIIT and VitD (HFD+HC+HII+VitD). Protein levels of BDNF and TrkB were assessed using Western blotting. Independent t-tests, one-way ANOVA, Tukey's test, and SPSS V.26 were used to analyze the data. Results: Consumption of HFD+HC resulted in a decrease in protein levels of BDNF and TrkB in the heart compared to ND (p<0.05). On the contrary, HIIT and VitD only resulted in a non-significant increase in protein levels of BDNF and TrkB in the heart compared to the HFD+HC group. However, the combination of HIIT and VitD resulted in a significant and non-significant increase in the protein levels of TrkB (P=0.03) and BDNF (P=0.06) compared to the HFD+HC group. Conclusion: HIIT+VD, by increasing cardiac BDNF and TrkB, may prevent the deleterious effects of high-fat and high-carbohydrate diets on this cardiac signaling, while each of these interventions alone has little effect on cardiac BDNF and TrkB.