Leptin

Is a 16 kDa protein hormone with important effects in regulating body weight, metabolism and reproductive function.

Hormone secreted by adipose tissue that acts to regulate long-term appetite and energy expenditure by signalling the state of body fat reserves.

A protein hormone that is produced by fat cells (adipose tissue) in the body. When leptin is produced and travels to cells whose surface bears leptin receptors (e.g., in the brain), those (brain) cells receive signal (transduction) indicating fullness/satiety.

Leptin has been found to be present in the bloodstream of obese humans at a concentration of approximately four times the concentration found in bloodstreams of lean humans. High levels of leptin present in the bloodstream disrupt some of the activities of insulin (hormone which regulates blood sugar levels), and may lead to diabetes.

A hormone that affects feeding behavior and hunger.

A hormone produced by fat cells that signals the body’s level of hunger to the hypothalamus of the brain.

A recently-discovered hormone that plays a major role in controlling hunger and metabolism. Leptin is a small molecule that must be administered by injection rather than by mouth, and is undergoing testing as a treatment for some forms of obesity.

A cytokine produced by the adipocyte. Leptin signals the brain that the fat store is full and that satiety has been attained. Mutation of either the leptin gene or the gene for its receptor has been associated with the development of obesity.

Leptin is a protein hormone synthesized from the ob gene in the adipose tissue and taken up by the brain where it inhibits the action of neuropeptide Y (NPY). Leptin appears to be important for normal reproductive function as well as for controlling body weight through regulation of appetite and energy expenditure. Leptin deficiency produces increased food intake and decreased energy expenditure resulting in obesity. Interestingly, obese individuals often have elevated concentrations of leptin, suggesting that leptin sensitivity and function are reduced. In animal models, and more recently humans, exogenous leptin administration has produced marked weight loss.

Protein hormone produced by adipose (fat) tissue. Its concentration in the body provides the brain with a rough indication of the body’s fat mass for the purposes of regulating appetite and metabolism. Binds to brain receptors, resulting in suppression of anabolic circuits and activation of catabolic circuits, causing decreased food intake and increased energy expenditure. Frank deficiencies in leptin secretion are a rare cause of human obesity. Blood concentrations of leptin are usually increased in obese humans, suggesting that they are in some way insensitive to it, rather than suffering from leptin deficiency. Thus, exogenous administration of leptin as a weight-loss technique have generally failed. Leptin also plays a role in female puberty, which will not usually occur until an adequate body mass is present. This may explain why very low body fat m human females is often associated with cessation of menstrual cycles.

A hormone produced by fat cells that is involved in appetite control and the regulation of body weight.

A hormone important in the regulation of body weight. Leptin is produced by fat cells and is believed to have a role in appetite control and weight gain and loss. Research indicates that administering injections of leptin to obese people may help them lose body fat. Study results have been promising but inconclusive. In some people, leptin does not work at all.

A helical peptide hormone produced by adipose tissue. Leptin acts on cells in the hypothalamus in response to increases in body fat storage to suppress appetite and increase energy expenditure. It also contributes to the onset of puberty and to the secretion of insulin by the pancreas.

When fat stores fall this appetite-suppressing hormone found in adipose tissues drops, signaling the hypothalamus to induce hunger.

Leptin, a hormone endogenously synthesized by the body, plays a pivotal role in conferring the sensation of fullness and constraining insulin release. The neuropeptide Y, an organic compound located in the brain that instigates appetite for carbohydrates and promotes insulin production, is a specific target of leptin that undergoes inhibition upon interaction.