Effect of Aerobic and Resistance Exercise on Browning of White Adipose Tissue in Rats

Objective:To compare the effect of aerobic and resistance exercise on browning of white adipose tissue (WAT) in rats. Methods:Sprague-Dawley rats were randomly assigned to three groups:control group (C) , aerobic exercise group (T) , resistance exercise group (L) . The rats of T group performed treadmill exercise, speed increase from 15m/min to 28m/min, and the time increased from 20 min to 60 min during 8 weeks, training were performed 5 days per week. The rats in L group were allowed to climb a 1.1m vertical ladder with weights attached to their tails and the weights were progressively increased. Sessions were performed one times per three days for 8 weeks. Then bilateral inguinal fat (in-WAT) and epididymal fat (ep-WAT) were isolated at 48 h after the last exercise section. The Hematoxylin –Eosin (HE) staining was used to observe The morphology of adipocyte, and the Quantitative Real-time PCR was used to detect the mRNA expression of browning genes. Result:The lipid droplets of in-WAT and ep-WAT in T group were smaller than that in C group, and some multilocular cells and blood vessels appeared in the in-WAT. The size of lipid droplets of in-WAT and ep-WAT decreased slightly in L group. The content of PRDM16, PPARγ, PGC-1αand UCP1 mRNA of in-WAT in T group increased significantly while that in L group increased with no significant compared with C group. All of these genes mRNA content of ep-WAT whether in L group or T group were lower than that in C group except PPARγ. Conclusion:The aerobic exercise can induce browning of subcutaneous WAT, but has no significant effect on visceral WAT. Resistance exercise has no effect on subcutaneous WAT and visceral WAT.