| Objective To observe the effects of dietary restriction on the expression of BDNF, brown adipose BMP8b in rats; as well as.the role in glucolipid.Methods Healthy six-week-old Sprague-Dawley(SD) rats (20) were randomly divided into2groups, each of groups consisted of10,①Ad libitum controlled group (group ALC),〥ietary restrictions group (group DR). Group DR was given60%of group ALC intake, to record given and remaining food of rats every day, the average food intake of group ALC calculated every two days and as the daily food intake of each rat of group DR after two days. Both groups were given standard diet. To measure weight and size of rats every week, which is able to calculate the Lee’s index. All rats were sacrificed at the end of15th week after food restriction invention, Serum samples were collected before sacrifice and divided into two, one for determine the levels of serum glucose,blood lipids, serum insulin,and calculate insulin sensitivity index(HOMA-ISI); another for determine the levels of BDNF and BMP8b by ELISA; took the hypothalamus and hippocampus and assay the expression of BDNF by RT-PCR,took the interscapular brown adipose tissue to weigh and detect the expression of BMP8b by RT-PCR, UCP1was detected by ELISA and RT-PCR in brown adipose tissue; took white adipose tissue around testis, perirenal and liver tissue to weigh, white adipose tissue was made HE slice of pathology to observe the morphological changes; the expression of NF-kB-. GLUT4were measured by RT-PCR.in white adipose tissue and liver tissue.Results1. There were no significant difference of body-weight and the Lee’s index between two groups before experiment (p>0.05); after diet restriction for15weeks, body-weight and Lee’s index were decreased extremely in group DR, compared with group ALC (p<0.01);2. The weight of white adipose tissue around testis and perirenal and adipose coefficient decreased significantly in group DR,compared with group ALC (p<0.01),the weight of brown adipose tissue decreased in group DR (p<0.05), but the brown adipose coefficient had no significant difference between two groups;3. Compared with the group ALC, The levels of fasting glucose, serum insulin, triglyceride (TG) decreased in group DR (p<0.05, p<0.01, p<0.01), high-density lipoprotein (HDL) levels and insulin sensitivity index (HOMA-ISI) increased significantly in group DR (p<0.01);4. Compared with the group ALC, The levels of BDNF mRNA in hypothalamus, BMP8b and UCP1mRNA in brown adipose tissue were lower in group DR (p<0.05,p<0.01), The levels of BDNF mRNA in hippocampus and the levels of BDNF in serum were higher in group DR (p<0.05), levels of BMP8b in serum and UCPlin brown adipose tissue homogenates were significantly lower in group DR (p<0.05,p<0.01);5. In group DR,the expression levels of NF-kB mRNA in white adipose tissue and liver tissue decreased (p<0.05), the expression levels of GLUT4mRNA was significantly higher in white adipose tissue (p<0.01), but no significant difference in liver,compared with group ALC;6. The levels of UCP1mRNA in brown adipose tissue were positively correlated with the levels of BDNF in hypothalamus and BMP8b in brown adipose tissue (r=0.559,p<0.01; r=0.628,p<0.01), the levels of UCP1in brown adipose tissue homogenates were positively related to the levels of BMP8b in serum (r=0.527,p<0.05);7. The levels of serum BDNF were negatively correlated with triglyceride (r=-0.757, p<0.01), and positively related to high density lipoprotein (r=0.517, p<0.05).Conclusion1. Dietary restrictions decrease the expression levels of BDNF in hypothalamus and BMP8b in brown adipose,which may cause the reduction of UCP1in brown adipose tissue.2. Dietary restriction improve insulin sensitivity in rat,which may related to higher levels of GLUT4in white adipose tissue, as well as lower levels of NF-kB in white adipose and liver. |
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