Parisa Ghanbari - Department of Sport Physiology, Behbahan Branch, Islamic Azad University, Behbehan, Iran
Sanaz Khajehzadeh - Department of Sport Physiology, Behbahan Branch, Islamic Azad University, Behbehan, Iran
Asieh Sayyed - Department of Sport Physiology, Behbahan Branch, Islamic Azad University, Behbehan, Iran
Davood Raeisi - Department of Internal Medicine, Faculty of Medicine, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran
Omidreza Salehi - Department of Physical Education and Sport Sciences, University of Kurdistan, Sanandaj, Iran

Objective: The aim of this study was to evaluate the effect of four weeks of high intensity interval training (HIIT) with beetroot juice supplementation (BJ) on serotonin and dopamine receptors in hippocampal tissue, as well as anxiety and depression in middle-aged diabetic rats.Materials and Methods: In this experimental study, ۲۸ diabetic female rats (۵۵ mg/kg, induced by streptozotocin) aged ۱۲-۱۴ months, weighing ۲۸۰-۳۲۰ g, were divided into (۱) diabetic control (DC), (۲) BJ, (۳) HIIT, and (۴) HIIT+BJ groups. Also, ۷ healthy rats were included in the healthy control (HC) group to evaluate the effect of diabetes induction on the research variables. HIIT was performed for four weeks, ۴ sessions per week (۷۰-۹۵% of maximum speed at high intensities; ۵۰-۶۰% of maximum speed at low intensities). Also, BJ was fed daily to rats at a dose of ۱۰ ml/kg.Results: Hippocampal expression of dopamine receptor-۱ (Dop.R), ۵-hydroxytryptamine receptor (۵-HT. R), open arm entry percentage (OAE%) and movement rate in the HIIT, BJ and HIIT+BJ groups were significantly higher than the DC group. In the HIIT+BJ group, open arm time percentage (OAT%) was higher than the DC group. Levels of Dop.R gene expression were more affected by HIIT, and levels of ۵-HT. R were more affected by BJ supplementation; also, HIIT+BJ had a synergistic effect on reducing anxiety and depression.Conclusion: Although HIIT was more effective than BJ and HIIT+BJ on Dop.R and BJ supplementation on ۵-HT.R and improved anxiety and depression, both of HIIT and BJ were complementary in improving dopamine and serotonin receptor-dependent anxiety and depression and enhanced each other's effects.

HIIT, Beta vulgaris, Serotonin receptor, Dopamine receptor, Aging, Diabetes