Adipokine And Obesity

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"In 1950, scientists working at the Jackson Laboratory in the US state of Maine discovered something extraordinary: Obese mice. The mice in question were born to normal weight parents. At first, the baby mice looked just like any other. But from the age of six weeks, they started eating, voraciously, never seeming to feel full. ... in May 1994, ... a eureka moment. ... that the gene must encode for a new type of hormone, one that regulates the body’s energy input. ... Leptin acts like a hunger blocker – if there’s enough fat, the mouse doesn’t need to spend time and energy looking for more food. But if fat storage runs low, leptin levels fall and stimulate appetite. ... After the mouse studies, leptin and its receptors were also found in humans. Giving those people leptin resulted in dramatic weight loss. For other people, this didn’t work. There are in fact many overweight people that produce plenty of leptin, but their bodies fail to respond to it. They have a different genetic mutation that gives them leptin resistance, similar to how type 2 diabetes makes people less sensitive to insulin. ... Fat, like the pancreas and the thyroid gland, is an endocrine organ. Part of a chemical messenger system, it makes biologically active compounds that regulate activity in distant parts of the body. A signalling protein secreted by fat cells is called an adipokine, and leptin was the first one ever found. We’ve since discovered hundreds of them. ... The leptin concentration in the blood is proportional to the fat amount of a person’s body because it is produced by fat cells. If we can detect the level of leptin in the blood serum sample of a patient, then you can directly measure the fat content. ... She created silver nanoparticles carrying anti-leptin antibodies on their surface; these are proteins that specifically bind to leptin."


Leptin | Podcast | Chemistry World (link contains a transcript of podcast): Rotund rodents revolutionised our understanding of the biological role of fat. Now, as Katrina Krämer discovers, the hormones created by fats could redefine obesity