Direct effects of leptin on brown and white adipose tissue.

摘要: Leptin is thought to exert its actions on energy homeostasis through the long form of leptin receptor (OB-Rb), which present in hypothalamus and certain peripheral organs, including adipose tissue. In this study, we examined whether has direct effects function brown white tissue (BAT WAT, respectively) at metabolic molecular levels. The chronic intravenous administration vivo for 4 d resulted a 1.6-fold increase glucose utilization index BAT, whereas no significant change was found after intracerebroventricular compared with pair-fed control rats, compatible effect BAT. WAT fat pads from lean Zucker Fa/ fa rats assessed ex vivo, where 9- 16-fold rate lipolysis observed 2 h exposure 0.1 10 nM leptin, respectively. contrast, obese fa/fa harbor an inactivating mutation OB-Rb. At level gene expression, treatment 24 increased malic enzyme lipoprotein lipase RNA 1.8+/-0.17 1.9+/-0.14-fold, respectively, while aP2 mRNA levels were unaltered primary cultures adipocytes Fa/fa rats. Importantly, however, these genes animals. presence OB-Rb receptors substantiated by detection transcripts RT-PCR, vitro activated specific STATs implicated signaling pathway Taken together, our data strongly suggest that BAT resulting activation Jak/STAT expression target genes, may partially account leptin-treated