The effect of High intensity interval training in normoxia and hypobaric hypoxia situation on the expression of genes involved in liver mitophagy in male Wistar rats fed a high fat diet

Consuming a high-fat diet leads to dysfunction of liver mitochondria and the occurrence of fatty liver disorders, and mitophagy, which plays a role in removing damaged mitochondria, can probably be effective in improving non-alcoholic fatty liver disease. The aim of this study was to determine the effect of nutrition, training and hypoxia on liver mitophagy in male Wistar rats.

Thirty-two male rats were randomly divided into four groups of eight including normal diet (ND), high-fat diet (HFD), high-fat diet and training in normoxia (HFD-HIIT) and high-fat diet and training in hypoxia (HFD-HHIIT). After determining the maximum aerobic velocity (MAV) in normoxia and hypoxia-hypobaric, the HIIT protocol was performed for 12 weeks and three sessions per week, which included 3 to 8 bouts 4-minute activity with an intensity of 80 to 93 percent of MAV and 2-minute active rest periods with an intensity of 50 percent of MAV. At the end, the levels of HIF-1α, Parkin and Fundc1 genes were measured through RT-PCR.

The expression of Parkin and Fundc1 genes in HFD-HIIT and HFD-HHIIT groups increased significantly compared to HFD (P<0.05). Also, the HFD-HHIIT group showed a significant increase compared to the HFD-HIIT group (P<0.05). Also, liver fat content and HIF-1α gene expression showed a significant decrease in HFD-HIIT and HFD-HHII groups compared to HFD (P<0.05).

It seems that training in hypoxic conditions compared to normoxia has an additional effect on increasing liver mitophagy and subsequently controlling liver fat content.