Adipocytokines and Metabolic Syndrome

Recently, adipocytes have been shown to be endocrine cells that secrete a variety of bioactive substances-the so-called adipocytokines. Among adipocytokines, tumor necrotizing factor alpha, plasminogen activator inhibitor 1, and heparin-binding epidermal growth factor-like growth factor are produced in adipocytes as well as already known organs, and they contribute to the development of vascular diseases. Visfatin is a very recently discovered visceral fat-specific protein that may be related to the development of obesity-related diseases such as diabetes mellitus and cardiovascular disease. In contrast to these adipocytokines, adiponectin, also a newfound adipose tissue-specific collagen-like protein, has been noted recently as an important antiatherogenic as well as antidiabetic protein. The function of adipocytokine secretion might be regulated dynamically by nutritional state. Visceral fat accumulation causes dysfunction of adipocytes including oversecretion of tumor necrotizing factor alpha, plasminogen activator inhibitor 1, and heparin-binding epidermal growth factor-like growth factor, as well as hyposecretion of adiponectin, which results in the development of a variety of metabolic and circulatory diseases. In this review, the importance of adipocytokines, including adiponectin, is discussed with respect to atherosclerosis.