The Effects Of 8-weeks Moderate Intensity Exercise On Lipophagy Of Obese SD Rats

Objective:The study aims to investigate the effect of 8 weeks of moderate intensity exercise on the level of autophagy in white adipose tissue of obese rats. Based on this, to further explore the effective exercise load for promoting the fat autophagy, and the possible mechanism of enhanced lipolysis in adipose tissue of exercise-trained rats.Methods:Firstly,40 11-week-old male SD rats were selected after 8 weeks adaptive feeding and divided into normal control group and high-fat group. These groups then further subdivided into exercise groups(control trained group, obese trained group) and sedentary groups(control sedentary group, obese sedentary group). The high-fat groups were continued expose to high-fat-diet in the following weeks (D12451). Secondly, the maximal oxygen uptake (V02max) were measured of all groups after 3 days adaptive training, and then made the exercise intensity for the first two weeks of exercise groups. After two weeks of training, the V02max of exercise groups were remeasured to make the exercise intensity of next two weeks, and so forth. In addition, the body weight of all groups were measured every week, and the body composition were measured after 7 weeks of training. Finally, abdominal aorta blood, epididymal white adipose and perirenal white adipose were collected at the end of 48h after the last week of training. The protein expression of LC3Ⅱ、LAMP2、Beclinl were examined by western blotting analysis.The LC32Ⅱ、LAMP2、Beclinl mRNA expression were analyzed by RT-qPCR.Results:1)After 8 weeks of intervention, the body weight of obese trained group was significantly lower than obese sedentary group(p< 0.01), and no significant difference was observed between control trained group and control sedentary group.2)The protein expression of LC3II and Beclinl in epididymis and perirenal white adipose of obese sedentary group were lower than the control sedentary group, but the protein expression of LAMP2 were significantly lower than the control sedentary group (p<0.05). The mRNA expression of LC3II, LAMP2, Beclinl in epididymal and perirenal white adipose were lower than the control sedentary group, but there was no significant difference.3) The protein expression of LC3Ⅱ,LAMP2 in epididymis and perirenal white adipose of obese sedentary group were significantly lower than obese trained group (p<0.05), while the mRNA expression of LC3 II, LAMP2, Beclinl in epididymal and perirenal white adipose were lower than obese trained group.4) The protein expression of LC3Ⅱ, LAMP2 and Beclinl in epididymis and perirenal white adipose of control sedentary group were lower than the control trained group, but no significant difference. Conclusions: 8 weeks high fat diet can significantly reduce abdominal white fat lipophagy activity in obese quiet rats, whereas 8 weeks of moderate-intensity exercise intervention can improve the obese rats abdominal white fat lipophagy activity.