[Animal modeling] Effects of 8-week aerobic exercise on skeletal muscle inflammation and exercise capacity in obese mice

  Objective To explore the effect of 8-week aerobic exercise on obesity induced by high-fat diet in mice.

  Methods Forty six C57BL/6 male mice were randomly divided into normal diet group and high-fat diet group to make obese mice models, and then randomly divided into control quiet group (CS group), control exercise group (CE group), obese quiet group (OS group) and obese exercise group (OE group). The exercise group received moderate aerobic exercise of 60% of the maximum exercise intensity for 8 weeks. Before and after the exercise intervention, the maximum exercise capacity of each group of mice was tested. During the intervention, the energy intake level and weight change of mice were detected. Forty eight hours after the last exercise, the gastrocnemius muscles of both hind limbs of mice were taken and frozen sections of skeletal muscle were made. The distribution of Desmin in skeletal muscle of mice was detected by immunofluorescence staining; HE staining was used to detect the cross-sectional area of skeletal muscle and inflammatory cell infiltration in mice. Western Blot method was used to detect the expression of skeletal muscle atrophy and inflammation related proteins in mice.

  Results Compared with CS group, the energy intake, body weight, Atrogin-1 protein, MuRF1 protein and TNF of OS group mice- α The protein expression was significantly increased (P<0.05), and the exercise ability, cross sectional area of skeletal muscle fiber, and IL-10 protein expression were significantly decreased (P<0.05). desmin="" protein="" was="" in="" after="" aerobic="" exercise="" compared="" with="" os="" there="" no="" significant="" difference="" energy="" intake="" of="" mice="" oe="" group="" p="">0.05). Body weight, Atrogin-1 protein, MuRF1 protein, TNF- α Protein and IL-1 β The protein expression decreased significantly (P<0.05), and the exercise ability, cross sectional area of skeletal muscle fiber, and IL-10 protein expression increased significantly (P<0.05); In addition, compared with CS group, CE group had Atrogin-1 protein, MuRF1 protein, TNF- α Protein and IL-1 β The protein expression decreased significantly (P<0.01), and the IL-10 protein expression increased significantly (P<0.05).

  Conclusion High fat diet related obesity can induce chronic inflammatory reaction of skeletal muscle, which leads to atrophy of skeletal muscle and decline of exercise ability; Aerobic exercise can effectively improve the skeletal muscle atrophy induced by obesity, and then play a role in improving exercise ability and obesity. Inflammation regulation in skeletal muscle tissue may be one of the important reasons.