UT Southwestern scientists discover leptin can also aid type 1...( DALLAS Aug. 25 2008 Terminally ill...),Health

DALLAS Aug. 25, 2008 Terminally ill rodents with type 1 diabetes have been restored to full health with a single injection of a substance other than insulin by scientists at UT Southwestern Medical Center.

Since the discovery of insulin in 1922, type 1 diabetes (insulin-dependent diabetes) in humans has been treated by injecting insulin to lower high blood sugar levels and prevent diabetic coma. New findings by UT Southwestern researchers, which appear online and in a future issue of the Proceedings of the National Academy of Sciences, suggest that insulin isn't the only agent that is effective. Leptin, a hormone produced by the body's fat cells, also lowers blood glucose levels and maintains them in a normal range for extended periods, they found.

"The fact that these animals don't die and are restored to normal health despite a total lack of insulin is hard for many researchers and clinicians to believe," said Dr. Roger Unger, professor of internal medicine and senior author of the study. "Many scientists, including us, thought it would be a waste of time to give leptin in the absence of insulin. We've been brainwashed into thinking that insulin is the only substance that can correct the consequences of insulin deficiency."

The mechanism of leptin's glucose-lowering action appears to involve the suppression of glucagon, a hormone produced by the pancreas that raises glucose levels. Normally, glucagon is released when the glucose, or sugar, level in the blood is low. In insulin deficiency, however, glucagon levels are inappropriately high and cause the liver to release excessive amounts of glucose into the bloodstream. This action is opposed by insulin, which tells the body's cells to remove sugar from the bloodstream.

In type 1 diabetes, which affects about 1 million people in the U.S., the pancreatic islet cells that produce insulin are destroyed. Type 1 diabetics must take insulin multiple times a day
'/>"/>