Leptin ELISA

Enzyme immunoassay for the quantitative determination of human Leptin in human serum and plasma. Leptin, the product of the ob gene, is a single-chain proteohormone with a molecular weight of 16 kD, which is thought to play a key role in the regulation of body weight. Its amino acid sequence exhibits no major homologies with other proteins. Leptin is almost exclusively produced by differentiated adipocytes. It acts on the central nervous system, in particular the hypothalamus, thereby suppressing food intake and stimulating energy expenditure. Leptin receptors - alternatively spliced forms exist that differ in length - belong to the cytokine class I receptor family. They are found ubiquitously in the body indicating a general role of leptin. A circulating form of the leptin receptor exists which acts as one of several leptin binding proteins. Besides its metabolic effects, leptin was shown to have a strong influence on a number of endocrine axes. In male mice, it blunted the starvation-induced marked decline of LH, testosterone, thyroxine and the increase of ACTH and corticosterone. In female mice, leptin prevented the starvation-induced delay in ovulation. Ob/ob mice, which are leptin deficient due to an ob gene mutation, are infertile. This defect could be corrected by administration of leptin, but not by weight loss due to fasting, suggesting that leptin is pivotal for reproductive functions.