Adipokine

The adipokines or adipocytokines are a group of cytokines (cell-to-cell signalling proteins) secreted by adipose tissue.

Members include:

* chemerin [MacDougald1, Ormond A. and Burant, Charles F. (September 2007) "The Rapidly Expanding Family of Adipokines" "Cell Metabolism" 6: pp. 159-161]
* interleukin-6 (IL-6) [Monzillo, Lais U. (2003) "Effect of Lifestyle Modification on Adipokine Levels in Obese Subjects with Insulin Resistance" "Obesity Research" 11(9): pp. 1048-1054]
* plasminogen activator inhibitor-1 (PAI-1)
* retinol binding protein 4 (RBP4)
* tumor necrosis factor-alpha (TNFα)
* visfatin

adiponectin, leptin ("Ob" ligand), and resistin are not adipokines (cytokines) as they do not act on the immune system. These substances produced by adipocytes are hormones. (Harrison's Principles of Internal Medicine). The definition of an adipokine is a cytokine produced by an adipocyte. A cytokine is a immunomodulating agent. Often in literature, proteins such as adiponectin, leptin, resistin are referred to as adipokines, however they can be more accurately put into the larger, growing list of adipose derived hormones.

Their relative roles in modifying appetite, insulin resistance and atherosclerosis are the subjects of intense research, as they may be modifiable causes of morbidity in people with obesity. [Matsuzawa, Yuji; Funahashi, Tohru and Nakamura, Tadashi (1999) "Molecular Mechanism of Metabolic Syndrome X: Contribution of Adipocytokines - Adipocyte-derived Bioactive Substances" "Annals of the New York Academy of Sciences" 892: pp. 146-54 [http://www.annalsnyas.org/cgi/content/abstract/892/1/146 Abstract] ] [Funahashi, T. "et al." (1999) "Role of adipocytokines on the pathogenesis of atherosclerosis in visceral obesity" "Internal Medicine" (Japan) 38: pp. 202-206 [http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Retrieve&db=PubMed&list_uids=10225688&dopt=AbstractPlus Abstract] ]

Notes