Dec 15, 2006

Diabetes breakthrough: Toronto scientists cure disease in mice

Dr. Dosch had concluded in a 1999 paper that there were surprising similarities between diabetes and multiple sclerosis, a central nervous system disease. His interest was also piqued by the presence around the insulin-producing islets of an "enormous" number of nerves, pain neurons primarily used to signal the brain that tissue has been damaged.

Suspecting a link between the nerves and diabetes, he and Dr. Salter used an old experimental trick -- injecting capsaicin, the active ingredient in hot chili peppers, to kill the pancreatic sensory nerves in mice that had an equivalent of Type 1 diabetes.
"Then we had the biggest shock of our lives," Dr. Dosch said. Almost immediately, the islets began producing insulin normally "It was a shock ? really out of left field, because nothing in the literature was saying anything about this."

It turns out the nerves secrete neuropeptides that are instrumental in the proper functioning of the islets. Further study by the team, which also involved the University of Calgary and the Jackson Laboratory in Maine, found that the nerves in diabetic mice were releasing too little of the neuropeptides, resulting in a "vicious cycle" of stress on the islets.

So next they injected the neuropeptide "substance P" in the pancreases of diabetic mice, a demanding task given the tiny size of the rodent organs. The results were dramatic.

The islet inflammation cleared up and the diabetes was gone. Some have remained in that state for as long as four months, with just one injection.