特異性：This item recognises leptin, a 16kDa secreted protein hormone encoded by the OB gene, which plays a key role in the regulation of metabolism, body weight and reproduction and is expressed primarily by white adipocytes, and to a lesser extent by stomach endothelium and the placenta. Regulation of food intake and energy expenditure by leptin is thought to predominantly occur in the hypothalamus of the brain, where leptin binds with high affinity to neuronal leptin receptors (OB-R), inhibiting the action of the feeding stimulants neuropeptide Y (NPY) and agouti-related peptide (AgRP), or promoting the effects of the appetite regulator a-melanocyte-stimulating hormone (a-MSH). Leptin also acts as a direct stimulator of fatty acid oxidation in the mitochondria of liver and skeletal muscle cells, and influences glucose and fat metabolism. The expression of leptin in relation to metabolic status is influenced by hormonal and metabolite control: stimulators of leptin include insulin and cortisol, whilst cAMP, thiazolidinediones and beta-adrenergic receptor agonists, reduce leptin expression.
