Renalase, also known as RNLS, is a flavin adenine dinucleotide-dependent amine oxidase that is secreted into the blood from the kidney. It is also suggested that RNLS functions as a hormone that metabolizes circulating catecholamines, which have an active role in the sympathetic and parasympathetic nervous systems. A high concentration of catecholamines activate plasma RNLS and promotes its secretion and synthesis.