Application of Leptin in Enhancing Immunity and Maintaining Obesity

Abstract

Leptin is predominantly generated in adipose tissue and circulates in serum both as a free and as a protein‐bound entity. Leptin, a 16 kDa nonglycosylated polypeptide product of the obese (ob) gene, is an adipocyte-derived hormone which has long been recognized as a key factor in regulating a wide range of biological responses involving energy homeostasis, neuroendocrine function, angiogenesis, bone formation and reproduction. Leptin is a key afferent signal linking adiposity level and nutritional status to neuroendocrine regulation of energy homeostasis chiefly through decrement in caloric uptake and enhancement in energy expenditure. Serum levels of leptin reflect the amount of energy stored in adipose tissue. Short-term energy imbalance as well as serum levels of several cytokines and hormones influence circulating leptin levels. Leptin acts by binding to specific receptors in the hypothalamus to change the expression of several neuropeptides that regulate neuroendocrine role and energy uptake and expenditure. Leptin plays a significant function in the pathogenesis of obesity and eating disorders and is thought to mediate the neuroendocrine response to food deprivation