Both acute and chronic inflammatory states are associated with decreased levels of high-density lipoprotein (HDL) cholesterol, yet the underlying mechanism is poorly understood. Endothelial lipase (EL), a recently described member of the triglyceride lipase family, has been shown to be a key enzyme in HDL metabolism. Expression of EL by endothelial cells is upregulated by proinflammatory cytokines and is associated with increased EL-specific triglyceride and phospholipase activity in vitro. Thus, EL may play an important role in lipid metabolism and energy homeostasis in states of acute and chronic inflammation.