The skinny on fat: lipolysis and fatty acid utilization in adipocytes

Lipolysis for the provision of fatty acids (FA) for other organs during times of energy demand occurs uniquely in white adipose tissue (WAT). Recent findings have identified a bona fide TAG hydrolase and the major adipose phospholipase A(2), AdPLA. By controlling PGE(2) levels, AdPLA dominantly regulates lipolysis in an autocrine/paracrine manner. Moreover, recent findings demonstrate that, surprisingly, increasing lipolysis in adipose tissue does not necessarily increase serum FA levels, which are usually correlated with insulin resistance. Rather, increasing lipolysis in adipose tissue causes a shift within adipocytes towards increased FA utilization and energy expenditure and thus protects against obesity. Here, we discuss the regulation of lipolysis and its effects on FA utilization within WAT and on insulin resistance.