Increasing Leptin, a protein involved regulating body weight I, in laboratory animals transforms fat-storing cells into unique fat-burning cells, researchers at UT Southwestern report. They speculate that these finding could prove “a quick and safe solution”. to the obesity problems in humans.

Researchers attribute the change in the cell’s structure and function rats- from fat-storing to fat-burning –to a massive increase in the action of mitochondria, the principal energy source of the cell. The increase in mitochondria, which also led to substantial weight loss in the rates, was found two weeks after researchers injected the leptin gene.

Finding from the study were in the Proceedings of the National Academy of Sciences and are available online. “There is the first careful examination of the fat cells after the leptin therapy,” said Dr. Roger Unger, director of the Touchstone Center for Diabetes Research at UT Southwestern Medical Center and the study’s senior author. “The structure of the cells changed from the normal appearance of a fat cell to a very novel cell that’s really never been seen before. There’s no precedent for a cell that appears like this.

“The ability to covert fat cells into fat-burning cells may suggest novel therapeutic strategies for obesity.”

Dr. Unger and his collaborators began working on this research in 1996. During the initial phase of the study, Dr. Unger observed that fat had disappeared in the fat cells, but at that time the researchers could only guess why.

“We predicted this in 1996, but until we showed the increase in mitochondria there was not any proof of what was happening, but there were many clues that the fat was being burned inside the cell,” said Dr. Unger, who hold the Touchstone/West Distinguished Chair in the Diabetes Research.

Collaborating with the research at the University of Geneva Medical School, who conducted morphological tests to analyze the form and structure of the cells, the scientists found in the PNAS study that instead of containing fat, the cells were crowded by mitochondria.

Researchers examined laboratory animals weighing between 280 grams (a little more than half a pound) and 300 grams. Some of the study subjects received an intravenous injection of the leptin gene, which was expressed in and produced by the liver; leptin level rose 50 times greater than normal in rats after two to four days before tapering off. The remaining laboratory animals followed a restricted diet.

Animals receiving the injection experienced a rapid and profound loss of fat compared to the animals that followed a restricted diet.