Adipokine

The adipokines or adipocytokines (Greek adipo-, fat; cyto-, cell; and -kinos, movement) are cytokines (cell-to-cell signaling proteins) secreted by adipose tissue.

Members include:


 * chemerin
 * interleukin-6 (IL-6)
 * plasminogen activator inhibitor-1 (PAI-1)
 * retinol binding protein 4 (RBP4)
 * tumor necrosis factor-alpha (TNFα)
 * visfatin
 * Leptin
 * Adiponectin
 * Apelin

As of 2008, the current terminology refers to a cytokine as an immunomodulating agent. However, conflicting data exists about what is termed a cytokine and what is termed a hormone and more research is needed in this area of defining cytokines and hormones. Under the current terminology, adiponectin, leptin (Ob ligand), and resistin are not appropriately considered adipokines (cytokines) as they do not act on the immune system. (Harrison's Principles of Internal Medicine). Often, these peptides (adiponectin, leptin, and resistin) are referred to as adipokines, however they can be more accurately put into the larger, growing list of adipose derived hormones.