Secretin is an endogenous peptide hormone involved in digestion and feeding behavior; it binds to its own GPCR secretin receptor. In adipocytes, secretin stimulates lipolysis, mediated by PKA and hormone-sensitive lipase (HSL) signaling; it also induces uptake of fatty acids and secretion of MCP-1 and adiponectin. Secretin enhances ambulation distance but not exploratory activity in animal models of repetitive hyperactivity. Additionally, secretin increases expression of tyrosine hydroxylase, stimulating catecholamine secretion in PC12 neurons.