Control of lipolysis by a population of oxytocinergic sympathetic neurons

Oxytocin (OXT), a nine amino acid peptide produced in the hypothalamus and released by the posterior pituitary, has well-known actions in parturition, lactation, and social behavior1, and has become an intriguing therapeutic target for diseases like autism and schizophrenia2. Exogenous OXT has also been shown to promote weight loss, among other beneficial metabolic effects1,3, suggesting that its therapeutic potential may extend to diabetes and obesity1,4. It is unclear, however, whether endogenous OXT participates in metabolic homeostasis. Here we show that OXT is a critical regulator of adipose tissue lipolysis in both mice and humans. In addition, OXT serves to license the ability of {beta}- adrenergic agonists to fully promote lipolysis. Most surprisingly, the relevant source of OXT in these metabolic actions is a previously unidentified subpopulation of tyrosine hydroxylase (TH)-positive sympathetic neurons. Our data reveal that OXT from the peripheral nervous system is an endogenous regulator of adipose and systemic metabolism.