Cellular regulation of lipolysis

Abstract

Lipolysis is the pathway by which adipocyte triglycerides are hydrolyzed and mobilized as free fatty acids, during periods when energy expenditure exceeds caloric intake. Hormone-sensitive lipase is the major enzyme involved in regulation of lipolysis. Numerous hormones acutely regulate lipolysis, but the most physiologically important are insulin (inhibitory) and catecholamines (stimulatory). Hormone-sensitive lipase is activated by phosphorylation in response to stimulatory hormones through a cAMP mediated cascade. Conversely, insulin and other hormones that inhibit lipolysis decrease phosphorylation of hormone-sensitive lipase. Lipolysis can also be regulated over the longer term by changes in gene expression in response to growth hormone, cytokines, insulin, and glucose. © 2006 Humana Press Inc.