Preliminary evaluation of β3-adrenoceptor agonist-induced ¹⁸F-FDG metabolic activity of brown adipose tissue in obese Zucker rat

Background: We have investigated β3-adrenoceptor agonist mediated brown adipose tissue (BAT) activation using ¹⁸F-FDG PET/CT in Zucker lean (ZL) and obese (ZF) rats. Methods: ¹⁸F-FDG was injected into ZL and ZF rats pretreated with saline or agonist CL316,243 for scans. ¹⁸F-FDG metabolic activity was computed as standard uptake values. Results: CL316,243 in ZL activated BAT up to 4-fold compared to saline, while ZF BAT was only up by 2 fold. The decreased activation was consistent with lower β3-adrenoceptor levels in ZF rats. Conclusions: The genetically modified ZL and ZF rats may provide a useful rat model to evaluate the significance of β3-adrenoceptor agonist-induced BAT activation in obesity