| Objective: To explore the protective mechanism of salidroside as a nutritional supplement in skeletal muscle during high-living and low-training,and reveal the skeletal muscle atrophy caused by high-living and low-training and the regulation of NF-κ B /MuRF1 signaling pathway.It provides theoretical guidance for improving the effect of altitude training.Methods : In this study,40 healthy male Wistar rats（10 rats in each group）at the age of 8 weeks were randomly divided into normoxic quiet group（Rc）,high-living low-training group（Hl）,hypoxic quiet group（Hq）,salidroside + high-living low-training group（Hs）.Simulated altitude 3500 meters,every night hypoxia exposure10-12 hours,daytime moderate intensity treadmill exercise,exercise time for 30 minutes a day,running 25 meters / min,a week six days exercise plus salidroside gavage.The dose was50 mg / kg.bw,once a day,six times a week.Result:（1）Body weight and skeletal muscle wet weight : from the fifth week,the Hl and Hs groups were significantly lower than those in the Rc group（P < 0.01）;the muscle morphology was observed.The extensor digitorum longus and gastrocnemius of Hl,Hq and Hs groups were smaller than those of Rc group,respectively.Compared with Rc,TP values in Hl and Hs groups decreased by 69 % and 33 %,respectively.（2）Physiological and biochemical indexes of rats : CK activity in Hs group was significantly lower than that in Hl group（P < 0.05）;b UN content in Hs group was significantly lower than that in Hq group（P < 0.01）;m DA content in Hq group was significantly higher than that in Hs group（P < 0.01）;m DA in Hl group was significantly higher than that in Hq and Hs groups（P < 0.01）;hs skeletal muscle and serum SOD were significantly higher than Hq（P < 0.05）;the NO content in skeletal muscle of Hs group was 5.2 % and 9.7 % higher than that of Hl and Hq groups,respectively.（3）Rat blood smear : the red blood cells in hypoxia exposure group were denser than those in normoxia quiet group,the red blood cells in Hl group were darker,the central light staining area was few or disappeared,and the cell volume was smaller;skeletal muscle sections : Hq group and Hl group compared with normoxia quiet group cells appeared swelling,loose arrangement,irregular nucleus shape.（4）Compared with Rc,NF-κB and MuRF1 m RNA in extensor digitorum longus of Hl,Hq and Hs increased（P < 0.05）;compared with Rc group,NF-κ B /MuRF1 m RNA in Hl and Hq gastrocnemius were significantly increased（P < 0.05）.（5）The NF-κB / MuRF1 protein expression in extensor digitorum longus of Hl,Hq and Hs groups was significantly higher than that in Rc group（P < 0.05）.NF-κB and MuRF protein in extensor digitorum longus and gastrocnemius of Hs were significantly lower than those of Hl（P < 0.05）.Conclusion :（1）Salidroside can significantly improve the negative effects such as weight loss,muscle atrophy,changes in erythrocyte morphology and weakening of function in rats caused by hypoxia during high living and low training.（2）Salidroside can reduce the oxidative stress induced by high-living and low-training,reduce the levels of CK,BUN and MDA in serum and skeletal muscle,increase the contents of T-SOD and NO,and improve lipid peroxidation and skeletal muscle blood supply.（3）Salidroside can reduce MuRF1 induced by high residence and low training in rats over expression of NF-κ B gene and protein.（4）Salidroside nutrition intervention can better overcome the skeletal muscle atrophy caused by high altitude hypoxia in high living and low training,so as to improve the training effect. |
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