Leptin May Help Solve Obesity Problem

Researchers have found that increasing leptin in laboratory animals transforms fat-storing cells into unique fat-burning cells, which has led them to speculate that this could provide "a quick and safe solution” to obesity in humans. Their findings were published in the February 9, 2004, online issue of Proceedings of the [U.S.] National Academy of Sciences.

Researchers from the University of Texas Southwestern Medical Center at Dallas (USA) collaborated with scientists at the University of Geneva Medical School (Switzerland) who conducted morphologic tests to analyze the form and structure of the cells. They found that instead of containing fat, the cells were crowded with mitochondria. Some of the lab animals received an intravenous injection of the leptin gene, which was expressed in and produced by the liver. Leptin levels rose 50 times greater than normal in rats after two to four days before tapering off. The remaining animals followed a restricted diet, and were constantly searching for food. The rats receiving leptin injections experienced a rapid and profound weight loss.

Leptin produced by fat cells does not ordinarily interfere with the accumulation of surplus fat, but leptin secreted by the liver does and actually causes the surplus to burn up. "We would like to break down the normal defense system against leptin produced in the fat cell. If we could disable or bypass this system and transform fat (storing) cells into fat-burning cells, then we may be a step closer to solving the obesity problem,” said senior author Roger Unger, M.D., director of the Touchstone Center for Diabetes Research at UT Southwestern.




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