Involvement of AMP-activated protein kinase in fat depot-specific metabolic changes during starvation.

The mechanisms controlling fat depot-specific metabolism are poorly understood. During starvation of mice, downregulation of lipogenic genes, suppression of fatty acid synthesis, and increases in lipid oxidation were all more pronounced in epididymal than in subcutaneous fat. In epididymal fat, relatively strong upregulation of uncoupling protein 2 and phosphoenolpyruvate carboxykinase genes was found. In mice maintained both at 20 and 30 degrees C, AMP-activated protein kinase was activated in epididymal but did not change in subcutaneous fat. Our results suggest that AMPK may have a role in the different response of various fat depots to starvation.