Effects Of Pressurizer Aided Methods On HIF-1αand Energy Metabolism In Rats Skeletal Muscle After High Intensity Exercise Under High Altitude Hypoxia

Objective: This experiment establishes animal model which moves rats to0.2-0.3MPa (Absolute Pressure2-3ATA)pressure cabin for restoring after highintensity exercise under high altitude hypoxia environment. The paper will discuss theeffects of high intensity exercise and pressurizer aided methods on the expression ofHIF-1α, GLUT-1and GLUT-4, the changes of LDH, SDH enzyme activity, and thefatigue recovery of rats skeletal muscle after the great intensity training in highaltitude hypoxia.Methods:56male Wistar rats were randomly divided into7groups:Group A isquiet control group; Group B restored in the natural environment; Group C restored1hour in0.2MPa pressure cabin; Group D restored2hours in0.2MPa pressure cabin;Group E restored1hour in0.3MPa pressure cabin; Group F restored in the naturalenvironment after hypoxia exercise; Group G restored1hour in0.3MPa pressurecabin after hypoxia exercise,8rats in each group. Average weight: Group A:197.71±16.87g，Group B:210.25±12.06g，Group C:208.38±4.75g，Group D:208.00±14.33g，Group E:210.88±11.99g，Group F:212.75±12.09g，Group G:210.50±8.53g. All the groups performed3-day adaptable training and6-day formaltraining in the Experimental Animal Center of Qinghai University (Xining,2260m).Running speed on the1st day of adaptable training is15m/min, increasing5m/min each day after each day’s training. The gradient in adaptable training is0°.Traininglasts15min in the1st day, the2nd is20min, the3rd is30min. Runningspeed on the1st day of formal training is25m/min, the2nd is30m/min, andmaintainthis running speed4days until the end of experiment. Gradient on the previous2daysis0°, which raised to10°on the3rd day. Another3days maintain this gradient to theend of experiment. Exercise timing of formal training is60min per day. On the7thday, all the groups except Group A takeexhaustion exercise whose running speed is35m/mim, gradient10°.According to the groups order of exhaustion exercise, GroupB to Group F went to pressure cabin for1hour. After24hours of pressure recovery,all the rats were anesthetized and one side of their gastrocnemius was taken down.Western blotting was used to detect protein expression of HIF-1α, GLUT-1, GLUT-4and LDH, SDH enzyme activity. Result:(1)Through1-week high intensity exercise under high altitude hypoxia, thisexperiment found the expression of HIF-1αpresenting the trend of dropping first, thenrising and dropping, especially Group B increased dramatically.(2)Through1-week high intensity exercise under high altitude hypoxia, thisexperiment found the expression of GLUT-1presenting the trend of rising first, thendropping and rising,especially Group G increased dramatically.(3)Through1-week high intensity exercise under high altitude hypoxia, thisexperiment found the expression of GLUT-4dropped first, and then rises, Group Gincreased dramatically.(4)Comparing group F and G, after pressurizer aided methods, LDH enzymeactivity of rats skeletal muscle increased.There is a significant difference betweenthese two groups (P <0.05).(5)After pressurizer aided methods, SDH enzyme activity of rats skeletal musclefrom group A to G presenting the trend of rising first, dropping and rising,thendropping.There was no difference among each group.Conclusion:(1)After using pressurizer aided methods, the increasing of protein expression ofHIF-1αof group C,D and E make transcription of target genes raised to increasesupplies of oxygen and nutrients in skeletal muscle, which is advantageous to fatiguerecovery after great intensity training in high altitude hypoxia.(2)Comparing group F and G, after pressurizer aided methods, there is anenormous rise in GLUT-1, GLUT-4, which could promote the glucose transportcapacity of skeletal muscle and increase glucose uptake in skeletal muscle cells. It isalso advantageous to the supply of energy material and fatigue recovery after greatintensity training in high altitude hypoxia.(3)After using pressurizer aided methods, LDH enzyme activity of skeletalmuscle in group C and E increased. There was difference among group F and G (P<0.05).The increasing of LDH enzyme activity in recovery groups which usedpressurizer aided methods could promote metabolism of lactic acid and pyruvic acid.This progress will decrease the content of lactic acid and promote the supply ofenergy in skeletal muscle,which is advantageous to fatigue recovery after greatintensity training in high altitude hypoxia.(4)After using pressurizer aided methods, there was no change in SDH enzymeactivity,which shows no effect onaerobic capacity.