Coming full circle: contributions of central and peripheral oxytocin actions to energy balance.

The neuropeptide oxytocin has emerged as an important anorexigen in the regulation of energy balance. Its effects on food intake have largely been attributed to limiting meal size through interactions in key regulatory brain regions such as the hypothalamus and hindbrain. Pharmacologic and pair-feeding studies indicate that its ability to reduce body mass extends beyond that of food intake, affecting multiple factors that determine energy balance such as energy expenditure, lipolysis, and glucose regulation. Systemic administration of oxytocin recapitulates many of its effects when administered centrally, raising the questions of whether and to what extent circulating oxytocin contributes to energy regulation. Its therapeutic potential to treat metabolic conditions remains to be determined, but data from diet-induced and genetically obese rodent models as well as application of oxytocin in humans in other areas of research have revealed promising results thus far.