The Effect Of High-intensity Interval Exercise On AMPK-PGC-1? Pathway In Skeletal Muscle Of Obese Rats

Objective:The purpose of this study was to research the effect of high-intensity interval training on weight loss from AMPK and PGC-1?and analyze the mechanism of the skeletal muscle's adaptation,by observing the effect of 8-week high-intensity interval training on body weight,the weight of fat,lipids,and expression of AMPK and PGC-1?in skeletal muscle of obese rats.Method:30 obese SD rats induced by high-fat diet were randomly divided into the control group?OC?,aerobic exercise group?OA?and high-intensity interval training group?HIIT?,10 in each group.The rats were still fed by high-fat diets.The OC didn't have any exercise,the OA and HIIT groups were given treadmill exercise with a gradient of 0.The total intervention time was 8weeks and 5 days/week.Each group of rats needs to test VO₂max before training,and the running speed is determined according to the VO₂max.After the fourth week of training,the running speed was adjusted.The OA exercised at a speed corresponding to 60%-70%VO₂max for 60 minutes;the HIIT conducted running at 90%VO₂max interspersed with recovery periods at 50%VO₂max and repeated that process 6 times,with a warm-up and cool-down period at 70%VO₂max.The time of HIIT exercise is determined by the distance of the OA group.Rats'blood,gastrocnemius muscle,perirenal fat and epididymal fat mass were taken in 24 hours after the 8th week of intervention.The TC?TG?HDLC and LDLC in serum were detected by enzymatic method and direct method.Quantitative Real-time PCR and western blot were used to test the expression of AMPK,PGC-1?gene and protein in gastrocnemius muscle.Results:?1?After 8 weeks of exercise intervention,the weights of rats in HIIT and OA were significantly lower than those in OC group?P<0.01?,but the weights of rats in HIIT was a litter higher than that in OA.The weight of perirenal fat and epididymal fat in the HIIT group were obviously lower than those in the OC group?P<0.01?,and the weight of the perirenal fat in the OA was obviously lower than that in the OC group?P<0.05?,the epididymal fat was lower than that in the OC group?P<0.01?.The weight of peripancreatic and epididymal fat in the HIIT were lower than than in OA by 21.3%and 22.4%.?2?The TC in HIIT group was very obviously lower than that in OC group?P<0.01?,TG and LDLC were obviously lower than those in OC group?P<0.05?.The TC in OA group was obviously lower than that in OC group?P<0.05?.There were no significant difference of HDLC in three groups.The TC?TG and LDLC in HIIT were lower than than in OA by 13.9%,21.4%and17.4%.?3?After 8-week exercise intervention,the relative expression of AMPK mRNA in HIIT group was higher than that in OC group by 9.6%and higher than that in OA group by 104%?P<0.05?,the expression of AMPK mRNA in OA group was lower than that in OC group?P<0.01?.The expression of AMPK protein in HIIT group and OA group were obviously higher in the OC group by 11%and 10%?P<0.05?.The expression of PGC-1?m RNA in HIIT and OA group was higher than that in OC group by 520%and 860%?P<0.01?,but the HIIT was lower than that in OA by 35.4%?P<0.01?.The expression of PGC-1?protein in HIIT group and OA group was higher than that in OC group by 9%and 18%,OA group was higher than that in HIIT group by 7%.Conclusions:?1?8-weeks of HIIT and aerobic exercise can reduced body weight and fat weight in obese rats obviously,and HIIT is better than aerobic exercise in reducing the fat weight.?2?HIIT and aerobic exercise can reduced the TC,TG and LDLC to improved the situation of blood lipids,and HIIT is better than aerobic exercise in improving the TG and LDLC.?3?HIIT and aerobic exercise can influence lipid metabolism in obese rats by AMPK-PGC-1?,and level of activation in HIIT is higher than aerobic exercise.