Circulating fats kill transplanted pancreas cells, s...( DALLAS Aug. 28 2007 Dietary restri...),Health

DALLAS Aug. 28, 2007 Dietary restrictions or other strategies that limit fat formation might make pancreatic cell transplants more effective, UT Southwestern Medical Center researchers report.

Using animal models, the researchers discovered that pancreatic islet cells transplanted into the liver fail not only because of immune rejection, but also because of overexposure to toxic fats that are synthesized by the surrounding liver cells and flood the pancreatic transplants. Their findings appear in the September issue of the journal Diabetes.

To date, a few hundred people have received transplants of complexes of pancreatic cells, called islets. The islets are implanted in the liver, where they at first make insulin, but over months or years their production often declines.

By understanding how fat affects these cells, maybe we can improve islet transplant and make it last a bit longer, said Dr. Roger Unger, professor of internal medicine at UT Southwestern and senior author of the study.

During islet transplantation, the pancreatic cell complexes are injected into a large vein that feeds into the liver, where they lodge. Cells within the islets, called beta cells, then produce insulin. The person receiving the transplant must take anti-rejection drugs.

Dr. Unger said that after two years, 87 percent of recipients must resume taking insulin, a problem that has led clinicians to investigate if the anti-rejection drugs are at fault, or if some other mechanism is at work.

In the current study, UT Southwestern researchers tested the hypothesis that fats in the liver might be killing the beta cells. The liver receives its blood supply directly from the digestive system, which provides a rich concentration of fats and sugars to the transplanted islet cells conditions the cells would not be exposed to in their normal environment in the pancreas. The researchers also theorized that the insulin that eac
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