Typically, the solution to type 1 diabetes is insulin. However, in an important laboratory recently (UT Southwestern Medical Center) a number of terminally ill rodents with type 1 diabetes have been restored to full health with a single injection of a substance other than insulin.
Type 1 diabetes (insulin-dependent diabetes) in humans has been treated since 1922 by injecting insulin to lower high blood sugar levels and prevent diabetic coma. New findings by UT Southwestern researchers, which will appear soon in the Proceedings of the National Academy of Sciences suggest that insulin isn’t the only agent that is effective. They've discovered that 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. This is really good news; it may lead at some point to a whole new way of treating Type 1 diabetics.
“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. This fellow, a professor of internal medicine and senior author of the study, says that many scientists thought it would be a waste of time to give leptin in the absence of insulin. He believes that many doctors have 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. Rsearchers tested whether a single injection of the leptin gene given to insulin-deficient mice and rats on the verge of death from diabetic coma could reverse the severe condition and prevent the animals from dying. The animals that received the leptin gene began producing excessive amounts of leptin, which reversed all the measurable consequences of type 1 diabetes including weight loss, hyperglycemia and ketoacidosis, a potentially fatal condition that develops when the body doesn’t have enough insulin to meet basic metabolic requirements.
“These animals were actually dying,” write the researchers. “But if we gave them the leptin gene, within two weeks, the terminally ill rodents were restored to full health without any other treatment.”