2022, Vol. 26 ›› Issue (29): 4598-4604

Effects of hypoxic exercise on skeletal muscle energy metabolism of rats with alimentary obesity

Wu Juhua1, Yang Yanan2, Weng Xiquan3, Zhao Fangfang4, Xu Guoqin3, Lin Wentao3, 4   

Abstract: BACKGROUND: The incidence of obesity is gradually increasing, which is prone to cause a variety of secondary diseases. Therefore, numerous weight-loss intervention strategies have been proposed, among which exercise intervention or/and hypoxic exposure have better effects on the prevention and treatment of obesity.
OBJECTIVE: To explore the effect of hypoxic exercise on the protein expression levels of peroxisome proliferators-activated receptor α (PPARα)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1)/Lipin1 in the skeletal muscle of rats with alimentary obesity.
METHODS: Animal models of alimentary obesity were established in rats, and the rat models were then randomized into normoxic quiet group and exercise group, 16.3% hypoxic quiet group and exercise group, and 13.3% hypoxic quiet group and exercise group. The rats were fed with high fat, and all exercise groups received an endurance exercise, 20 m/min, 40 min/d, 5 days per week for 8 weeks. The rats were killed under anesthesia and sampled at 24 hours after the last exercise. The protein expression levels of PGC-1α, PPARα, and Lipin1 in the skeletal muscle of rats were then determined by western blot and immunohistochemistry.
RESULTS AND CONCLUSION: The rat model of alimentary obesity was induced by a 7-week high-fat diet. Compared with the normoxic quiet group, the expression of PGC-1α protein in the skeletal muscle of rats was significantly increased in the normoxic exercise group, 16.3% hypoxic exercise group, and 13.3% hypoxic exercise group (P < 0.05-0.01). Compared with the 16.3% hypoxic quiet group, the expression of PGC-1α protein in the skeletal muscle of rats was significantly increased in the 16.3% hypoxic exercise group (P < 0.05). Compared with the 13.3% hypoxic exercise group, the expression of PGC-1α protein in the skeletal muscle of rats was significantly reduced in the normoxic exercise group, 16.3% hypoxic quiet group, and 13.3% hypoxic quiet group (P < 0.05-0.01). Compared with the normoxic quiet group, the expression of PPARα protein in the skeletal muscle of rats was significantly increased in the normoxic exercise group, 13.3% hypoxic quiet and exercise groups (P < 0.05-0.01). Compared with the 13.3% hypoxic exercise group, the expression of PPARα protein in the skeletal muscle of rats was significantly reduced in the 16.3% hypoxic quiet and exercise groups (P < 0.05). Compared with the normoxic quiet group, the expression of Lipin1 protein in the skeletal muscle of rats was reduced in the other five groups, and reduced significantly in the 13.3% hypoxic exercise group (P < 0.05). To conclude, hypoxic exercise can increase the expression of PGC-1α and PPARα and reduce the expression of Lipin1 protein in the skeletal muscle of obese rats, and promote the oxidative metabolism of fatty acids in the skeletal muscle, which is beneficial to improving skeletal muscle energy metabolism of obese rats.
Key words: hypoxic exercise, obesity, PGC-1α, PPARα, Lipin1, skeletal muscle, rat