[The central melanocortin system and its role in energy homeostasis].

Obesity is an important health concern, and the central melanocortin system is likely to play an important role in both normal regulation of energy homeostasis as well as genetic predisposition to obesity. Three different mouse models of obesity have been created by virtue of mutations which alter the function of the melanocortin system, and a rare form of human obesity has been characterized in two families with mutations in the proopiomelanocortin gene [26]. More recently published works suggests an association between common childhood obesity and dominant inheritance of a single null allele of the melanocortin-4 receptor [44, 49]. Experimental work in the rodent suggests that the central melanocortin system may be a fundamental component of the adipostat, the mechanism by which constant energy stores are maintained. This hypothesis is the subject of this review.