Effects Of High Intensity Interval Training On Fatty Hydrolases Activation In Different Adipose Tissues Of Obese Mice

Objective: Obesity is prevalent all over the world,which is harmful to human health.So it is imperative to prevent fat and lose weight.Traditional weight loss methods use moderate intensity continuous training to increase energy consumption.Lately,high intensity interval training is widely used because of its short time and intermittent,which also has the effect of weight loss.It is found that overcoming the same mechanical work,high intensity interval training can not only reduce subcutaneous fat,but also reduce the amount of abdominal visceral fat,the internal mechanism is not clear.In this experiment,C57BL/6 mice were used to simulate high intensity interval training.To observe the activation of adipose hydrolase in different parts of white adipose tissue by high intensity interval training in order to explore the possible mechanism of reducing the weight of visceral adipose tissue.Method: Three-week-old female C57BL/6 mice(weighing 9.67?1.12g),were randomly divided into normal diet group(C,n = 10)and high-sugar and high-fat diet group(H,n = 60).After one week of adaptive feeding,they were randomly divided into two groups: normal diet group(C,n = 10)and high glucose and high fat diet group(H,n = 10).H group was fed with a high glucose and high fat diet for 15 weeks(high-sugar and high-fat diet: 60% standard diet,16% sugar,5% lard,18% egg yolk powder and 1% sodium cholate).The weight and diet of mice were recorded weekly.The standard of obese mice model: the body weight of H group was more than 10% of the average body weight of C group,which were regarded as diet-induced obese mice.Subsequently,30 obese mice were randomly divided into three groups: Obese quiet control group(HDF),moderate intensity continuous training group(MICT)and high intensity interval training group(HIIT).The mice in MICT group and HIIT group were treated with treadmill exercise for 12 weeks(5 times a week).The specific scheme was as follows: the MICT group exercised for 45 minutes at 50%~70% maximum oxygen uptake peak intensity,and the HIIT group exercised for 1 minute at 90% ~110% maximum oxygen uptake peak intensity,then exercise at 50% ~70% maximum oxygen uptake peak intensity for 2 minutes.After 12 cycles of high intensity interval exercise,the total distance of each treadmill exercise was equal in the two groups.After 12 weeks of exercise intervention,the body weight,Lee's index,subcutaneous and visceral fat weight of mice were measured.Serum triglyceride,total cholesterol,high density lipoprotein and low density lipoprotein were measured by colorimetry.The proteins expressions of ATGL,HSL,HSL-ser660,HSL-ser563 and HSL-ser565 in subcutaneous and visceral adipose tissues were detected by Western blot.The indicators of body weight,Lee's index,subcutaneous fat weight,visceral fat weight,serum triglyceride,total cholesterol,high density lipoprotein and low density lipoprotein levels were analyzed by covariance analysis.The indicators of HSL,HSL-ser563,HSL-ser565,HSL-ser660 and ATGL were analyzed by one-way ANOVA.P<0.05 was considered to be significant difference,P<0.01 was considered to be very significant differenceResult:(1)The body weight of mice in HIIT group and MICT group was significantly lower than that in HFD group(P < 0.01),but there was no significant difference between HIIT group and MICT group(P > 0.05).The Lee's index of HIIT group was significantly lower than that of HFD group(P < 0.05),but there was no significant difference in Lee's index among the other groups(P > 0.05).The visceral fat weight of HIIT group was lower than that of HFD group and MICT group(P < 0.01),but there was no difference between HFD group and MICT group(P > 0.05).The subcutaneous fat weight of HIIT group and MICT group was lower than that of HFD group(P < 0.05),but there was no difference between HIIT group and MICT group(P > 0.05).(2)After 12 weeks of exercise intervention,there was no significant difference in HDL-C,TG and TC among the three groups(P > 0.05),but the level of LDL-C in HIIT group was lower than that in HFD and MICT groups(P < 0.01 and P < 0.05).(3)There was no significant difference in the protein expression of HSL in visceral fat and subcutaneous fat among the three groups(P > 0.05).The phosphorylation expression of HSL-ser563 in visceral fat of HIIT group was significantly higher than that of HFD group and MICT group(P < 0.05),but there was no significant difference between HFD group and MICT group(P > 0.05).The phosphorylated expression of HSL-ser660 in visceral fat in MICT group was significantly higher than that in HFD group(P < 0.05).The phosphorylated expression of HSL-ser660 in subcutaneous fat of MICT group was significantly higher than that of HFDgroup and HIIT group(P < 0.05).There was no significant difference in the phosphorylation expression of visceral fat HSL-ser565,subcutaneous fat HSL-ser563 and ser565 among the three groups(P > 0.05).(4)There was no significant difference in the expression of ATGL protein in visceral fat among the three groups(P > 0.05).The protein expression of ATGL in subcutaneous fat of MICT group and HIIT group was significantly higher than that of HFD group(P < 0.05).Conclusion:12 weeks of HIIT and MICT exercise can reduce subcutaneous fat weight in obese mice,and HIIT exercise could improve the dyslipidemia and reduce visceral fat weight in obese mice.Both HIIT and MICT exercise could activate the activities of ATGL and HSL in subcutaneous adipose tissue by up-regulating the protein expression of ATGL and HSL-ser660 in subcutaneous adipose tissue,but only HIIT exercise could activate the activity of HSL in visceral adipose tissue by up-regulating the expression of HSL-ser563 protein in visceral adipose tissue.The activation of visceral fat HSL by HIIT may be one of the mechanisms of reducing visceral fat weight and the changes of related cell signaling pathways still need to be further explored.