Fu-Lin Lu1,Ling-Heng Kong2, *
1The Athletic Department of Xi’an Medical University, Xi’an - 2Department of Basic Medicine, Xi'an Medical College, Xi’an, China
Introduction: To investigate the improvement effect of long-term vitamin D supplementation on skeletal muscle fatigue in rats and related mechanism.
Materials and methods: The skeletal muscle fatigue rats were prepared and divided into four groups according to whether vitamin D was supplemented and whether there was skeletal muscle fatigue, namely control group (Con), exercise group (Exe), control + vitamin D supplementation group (Con+VD) and Exercise + vitamin D supplementation group (Exe + VD). The levels of vitamin D, serum IL-1β, TNF-α and IL-6 in rats were detected by Elisa; the exercise ability of rats was observed by open field test and rotating rod fatigue test. The levels of IL-1β, TNF-α and IL-6 in rat gastrocnemius muscle were detected by RT-PCR. The expressions of NLRP3 and Caspase-1 in the gastrocnemius muscle of rats were detected by Western Blot.
Results: The vitamin D level decreased significantly in the Exe group, but increased significantly in Con+VD and Exe+VD; the exercise ability decreased significantly in the Exe group, but increased significantly in Exe+VD; the inflammation level of the rats was significantly higher in the Exe group than in the other three groups. Skeletal muscle IL-1β was significantly negatively correlated with 25(OH)D3, 1,25(OH)2D3, walking distance, rod time, and rod rotation speed. The expression of NLRP3 and Caspase-1 was significantly increased in the Exe group, but decreased significantly after vitamin D supplementation.
Conclusion: Vitamin D supplementation can alleviate the muscle fatigue state and improve the exercise ability of overtraining rats by regulating the inflammation level in the body.
Vitamin D, Skeletal muscle fatigue, Inflammation level, NLRP3.