Effect of electroacupuncture on the expression of PGC-1α and UCP-1 in the brown adipose tissue of obese rats

摘要

Objective:To explore the effect of peroxisome proliferators-activated receptor γ coactivator-1α (PGC-1α) and uncoupling protein-1 (UCP-1) in the brown adipose tissue (BAT) of obese rats in the process of acupuncture treatment for obesity.Methods:Fifty clean-grade male Wistar rats with the age of 3 months were randomly divided into highfat diet group (n=40) and normal diet group (control group,n=10).Nutritional obesity animal models were established through feeding with high-fat diet.Twenty-four animal models in the high-fat diet group were established successfully,and then they were randomly divided into model group,acupuncture group and non-acupoint group,with 8 rats in each group.In acupuncture group,Zúúsānlǐ (足三里ST 36) and Tiānshū (~ST 25) were selected.In non-acupoint group,the non-acupoints located on 5 mm beside ST 36 and ST 25 were selected as acupuncture points,and electroacupuncture intervention was adopted for 5 times/week for 8 weeks.The body mass of obese rats was measured,the body fat ratio in BAT of rats was calculated,and the expression levels of PGC-1α and UCP-1 in BAT of rats were detected by immunohistochemical method.Results:① After treatment,the body mass of rats in acupuncture group reduced significantly,which increased in the other three groups.The changing value of body mass of rats in acupuncture group was higher than that in model group (P ＜ 0.05),the changing value of body mass of rats in acupuncture group was higher than that in non-acupoint group (P ＜ 0.05) and the difference in body mass changing value of rats between non-acupoint group and model group was not statistically significant (P ＞ 0.05),the body fat ratio in BAT of rats in non-acupoint group was lower than that in acupuncture group,and the differences were statistically significant (P＜ 0.05).② Compared with model group,the body fat ratio in BAT of rats in acupuncture group increased significantly (P ＜ 0.05),and the difference in body fat ratio in BAT of rats between non-acupoint group and model group was not statistically significant (P ＞ 0.05).③ Compared with model group,the PGC-1α and UCP-1 levels in BAT of obese rats in acupuncture group increased (P ＜ 0.05),and the difference in expression levels of PGC-1α and UCP-1 in BAT of rats between non-acupoint group and model group was not statistically significant (P ＞ 0.05),the expression levels in non-acupoint group were lower than that in acupuncture group,and the differences were statistically significant (P ＜ 0.05).Conclusion:Electroacupuncture at "ST 36" and "ST 25" can effectively up-regulate the expression levels of PGC-1α and UCP-1 of diet induced obesity rats,it indicates that "ST 36" and "ST 25" have close relationship with obesity and it is may be one of the effect mechanisms of electroacupuncture in losing weight through facilitating the "browning reaction" of white adipose tissue.