Objective:Through the establishment of high-intensity endurance training and exhaustive swimming damage model

to investigate the function of anti-fatigue

maintaining the osmotic pressure of cell membrane and the balance of transmembrane potential of Siraitia grosvenori Leaves Flavonoid.Method: Forty healthy male Sprague-Dawley rats(2-3 months old;body weight of（200±20） g were randomly divided into five groups（n=8）: quiet control group

quiet exhaustive exercise group

quiet-administration exhaustive exercise group

training exhaustive exercise group and training-administration exhaustive exercise group.The rats in all drug treated groups were intragastrically administrated by S.grosvenori leaves flavonoid extract（20.0 g·L-1） at the dose of 10.0 mL·kg-1·d-1（200 mg·kg-1）

while the rats in unadministrated groups were treated by physiological saline solution according to the same dose.The rats in each group were trained by 3% weight-bearing exhaustive swimming after four-week increasing load swimming training.Blood samples were collected when all rats were killed immediately by decapitation after the accurate records of exhaustive time to determin the relevant indicators of ATPase in quadriceps.Result: At the point of immediately after exhaustive exercise

the activity of Na+/K+-ATPase was extremely significantly decreased（P<0.01） in all the exhaustive exercise groups except the training-administration exhaustive exercise group.The activity of Na+/K+-ATPase was significantly higher in the training-administration exhaustive exercise group than that in other exhaustive exercise groups

but it was no significant difference compared to quiet control group.The activity of Ca2+ATPase was also decreased at the point of immediately after exhaustive exercise in all the exercise groups.Ca2+ATPase activity in training-administration exhaustive exercise group was significantly lower than that of quiet control group.While Ca2+ATPase activities in administration exhaustive exercise group and training exhaustive exercise group were significantly higher than that of quiet exhaustive exercise group（P<0.05

P<0.01）

Ca2+ATPase activities were appeared upward trend

though these data had no statistically significance.At the point of immediately after exhaustive exercise

the activity of total ATPase was significantly decreased

though the total ATPase in administration exhaustive exercise group and training exhaustive exercise group were significantly higher than that of quiet exhaustive exercise group（P<0.01）

and it in training-administration exhaustive exercise group was significantly higher than that of quiet-administration exhaustive exercise group and training exhaustive exercise group（P<0.01）.Conclusion: Na+/K+-ATPase

Ca2+/Mg2+-ATPase and total ATPase in quadriceps of swimming exhaustive rats could increased by administration of S.grosvenori leaves flavonoid.This data indicated that Siraitia Grosvenori leaves flavonoid has important significance to maintain the osmotic pressure of cell membrane and the balance of transmembrane potential.And the S.grosvenori leaves flavonoid could also maintain the balance of Ca2+/Mg2+ to ensure higher energy supply

improve the capacity of anti-oxidant

and delay the onset of exercise-induced fatigue.