Fig. 3. Effects of resveratrol (RSV) on the differentiation and activation of brown adipocytes in Otsuka Long Evans Tokushima Fatty (OLETF) rats. (A) Hematoxylin and eosin staining for brown adipocytes. Brown adipose tissue was collected from OLETF rats at 36 weeks of age. With the treatment of RSV and feeding of the high fat diet (HFD), the differentiation of brown adipocytes increased. (B) The number of brown adipocytes visible in the high-power field increased significantly with RSV treatment and HFD feeding. The average number of brown adipocytes was calculated at four sites of each section. The number of rats in each group is described in the Methods. (C) Western blotting for mitochondrial activity and estrogen receptor α (ER-α). (D) Relative expression in Western blotting, determined using a densitometer. All protein lysates were evaluated and compared with those of rats on the standard diet. SD, standard diet; HF, high fat; UCP-1, uncoupling protein 1; p-AMPK, phospho-AMP-activated protein kinase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase. ^aP value below 0.05 with treatment of RSV in each diet group (Mann-Whitney U test).