EFFECT OF HIGH-INTENSITY INTERVAL TRAINING AND LOW-INTENSITY ENDURANCE TRAINING ON PPARΓGENE EXPRESSION AND VISCERAL ADIPOSE TISSUE TRIGLYCERIDE CONTENT IN RATS WITH NAFLD

The peroxisome proliferator-activated receptor gamma (PPARγ) expression in visceral adipose tissue extensively cause recovery of non-alcohol fatty liver (NAFLD) and insulin signaling regulation. The main purpose of this study was to compare the effect of an eight-week low-intensity endurance training (LIET) and high-intensity interval training (HIIT) on the amount of PPARγ gene and TG content of visceral lipid tissue in Wistar male rats affected by non-alcohol fatty liver(NAFLD).

The present research was performed on 40 Wistar rats affected by NAFLD. The rats were divided into four groups. Healthy Control (Standard Diet), control, LIET, and HIIT (High-fat diet). After 16-weeks of using a special diet, ALT enzyme serum level was obtained from the mentioned groups and, as the main symptoms of fatty liver, it was found that consuming fatty foods could develop NAFLD disease in the experimental group. Then the experimental groups were divided into; control, HIIT, and LIET groups randomly and they consumed fatty foods constantly until the end of practice or training period. HIIT training protocol consisted of 2 min running session with 75% more speed intensity in the first week, 80% more speed in the second week, 85% in the third week, and 90% in the fourth week, to the end of the training. The LIET training protocol composed of running with 45% maximum speed intensity. The PPARγ gene expression was evaluated by real-time PCR technique and TG measurements of visceral lipid tissue using an  AutoAnalyzer (BT3000 model).

Analysis of the present data showed that there was no significant difference in the level of visceral fat PPARγ gene expression between different groups (p = 0.060). However, there was a significant difference in TG content between the control group and low-intensity endurance training (p = 0.001) and between the control group and intense periodic training (p = 0.001). There was also a significant difference in TG content between low-intensity endurance training and intense intermittent training (p = 0.003).

It could be concluded that exercise with continued high-fat diet did not affect PPARγ expression of visceral adipose tissue. Exercise independent of PPARγ pathway will affect visceral fat content in rats with NAFLD. On the other hand, reduction in visceral TG levels in exercise groups could occur independently of weight loss.