Mechanism Of High-intensity Interval Training To Alleviate The Resistance Of Catecholamines In Fat Cells Of Obese Mice And Improve Lipolysis

Objective: Numerous studies have found that high-intensity interval training(HIIT)has the same or better fat loss effect than medium-intensity continuous training(MICT),especially in reducing visceral fat.Obesity can cause fat cells to resist the state of lipolysis hormones such as catecholamines,make fat breakdown difficult,and increase obesity.MICT has been proven to improve the lipolytic resistance caused by obesity and restore fat hydrolysis to normal.This is one of the key mechanisms that MICT has a weight loss effect.Whether HIIT has a more significant effect on improving lipolytic resistance than MICT and thus achieves better weight loss effects needs further exploration.Therefore,in this study,C57 BL / 6 female mice were first fed a high-fat diet for 14 weeks to build an obesity model,and then subjected to 12-week HIIT and MICT interventions.Furthermore,the mature adipocytes were isolated for adrenaline stimulation in vitro,and the activity of fat hydrolase and lipid bond rupture in the adipocytes were observed,which reflected the improvement effect of HIIT on lipolysis resistance of adipocytes,and the internal mechanism of HIIT with good weight loss effect was explored.Method: Three-week-old C57 BL / 6 female mice(body weight 9.67 1.12g),after one week of adaptive feeding,were randomly divided into a common diet group(group C,n = 12)and a high-sugar and high-fat diet group(group H,n = 70 only).Group H was fed with a high-fat diet for 14 weeks(high-sugar and high-fat diet: 60% standard feed,16% white sugar,5% lard,18% egg yolk powder,and 1% sodium cholate)to replicate a mouse obesity model.The weight of group H mice was more than 10% of the average weight of group C,and they were regarded as diet-induced obese mice.Subsequently,36 obese mice were randomly divided into obese quiet control group(HDF group),medium-intensity continuous training group(MICT group)and high-intensity intermittent training group(HIIT group).MICT group and HIIT group mice were subjected to treadmill training for 12 weeks(exercise 5 times a week).The specific scheme is: the mice in the MICT group exercise for 50 minutes at a peak intensity of 50% to 70% of the maximum oxygen uptake,and the mice in the HIIT group exercise for 1 minute at a peak intensity of 90% to 110% of the maximum oxygen uptake,at 50% to 70% Maximum oxygen uptake peak intensity exercise for 2 minutes,12 high-intensity intermittent exercises cycled,the total distance of each group of mice in each exercise was equal.After 12 weeks of training,the body weight,subcutaneous and visceral fat weight of the mice were measured;the volume of subcutaneous and visceral adipocytes of the mice was observed by HE staining;primary mouse adipocytes were isolated,adrenaline incubated,and subcutaneously tested by Western blotting And visceral adipocyte HSL-ser563 protein levels;Fourier transform infrared spectroscopy was used to detect the number of lipid bonds in mouse visceral and subcutaneous adipocytes.The experimental data were expressed as "mean ± standard deviation".Weight results were analyzed by single factor analysis of variance;FITR spectrum AUC index and different adipose tissue weights and and HSLser563 protein expression indicators were analyzed by two factor analysis of variance.P <0.05 indicates that the difference is significant,and P <0.01 indicates that the difference is extremely significant.Result:(1)The average weight of obese mice in the HIIT and MICT groups was lower than that in the HFD group,and the differences were extremely significant(P <0.01).There was no significant difference in body weight between the two training groups;the subcutaneous fat in the groin of the mice in the HIIT and MICT groups Weight and visceral fat weight around the uterus were lower than those in the HFD group,the difference was significant(P <0.05)or extremely significant(P <0.01);the visceral fat weight of the mice in the HIIT group was lower than that in the MICT group,and the difference was extremely significant(P <0.01),there was no significant difference in subcutaneous fat weight between HIIT and MICT mice.(2)The volume of subcutaneous and visceral adipocytes in the HIIT and MICT groups was significantly smaller than that in the HFD group.Western Blot results showed that the protein content of HSLser563 in HIIT group and MICT group was higher than that in HFD group in subcutaneous adipose tissue after NE stimulation.The difference was extremely significant(P <0.01),but there was no Significant difference.In the visceral adipose tissue,the HSLser563 protein content in the HIIT group was higher than that in the HFD group and the MICT group,and the differences were extremely significant(P <0.01),but there was no significant difference between the MICT group and the HFD group.(3)Western Blot results showed that HSLser563 protein expression in visceral adipocytes of HIIT group was higher than that in HFD group and MICT group after adrenaline stimulation,and the difference was extremely significant(P <0.01);MICT group and HFD group mouse viscera There was no significant difference in the expression of HSLser563 protein in adipocytes;the expression of HSLser563 protein in subcutaneous adipocytes of HIIT group and MICT group was higher than that of HFD group,and the difference was extremely significant(P <0.01),but between the two exercise groups No significant difference.(4)The results of FTIR experiments showed that the number of lipid bonds in visceral adipocytes of HIIT group and MICT group was less than that of HFD group,which had extremely significant differences(P <0.01)and significant differences(P <0.05).The number of bonds is less than that in the MICT group,which has a significant difference(P <0.05).The number of lipid bonds in subcutaneous adipocytes of the HIIT group and the MICT group is also less than that in the HFD group,which have extremely significant differences(P <0.01).Sexual difference(P <0.05),and the number of lipid bonds in the HIIT group was less than that in the MICT group,which had a significant difference(P <0.05).Conclusion:The improvement effect of HIIT training on fat cell lipolytic resistance in obese mice was better than that of MICT in 12 weeks,and the improvement effect of HIIT on visceral adipocytes was better than that of subcutaneous fat cells.One of the key mechanisms for better visceral fat effect.