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100 Years of Insulin

100 Years of Insulin
The idea for insulin came to Frederick Banting in the wee hours of the morning of October 31, 1920. Waking from a fitful sleep, Banting scribbled down a 25-word hypothesis that, within the span of a year, would lead to one of the most significant medical discoveries of the 20th century. With no lab space or research experience, Banting approached University of Toronto physiology professor J.J.R. Macleod—an international expert in diabetes—who agreed the idea was worth testing, on the condition that Banting agree to devote all his energies to the project. They spent the spring and summer testing Banting’s theory and in the winter of 1921 they were able to purify the extract and begin human trials. On January 23, 1922 Leonard Thompson, a 14-year-old Toronto boy who was drifting in and out of consciousness at Toronto General Hospital, became the first person to receive the purified extract of what would come to be called “insulin.” Insulin’s effect on diabetic patients was nothing short of miraculous. Bill Bigelow, a young U of T surgeon who witnessed the early insulin trials, recalled seeing comatose patients “awakened dramatically, snatched from death’s door.”

There have been millions of lives both human and animal saved and made better by insulin. Before 1921 they did know about the role that insulin played in the body and its connection to diabetes was well established, but this was the first time that an effective treatment was possible. The Toronto researchers couldn’t mass produce insulin, but the company Eli Lilly could as least in the United States. Eli Lilly is headquartered in Indianapolis, and at the time, was convenient proximity to many stockyards. This allowed access to frozen pancreases from pigs and cows to keep up with demand—there were an estimated one million Americans who needed insulin—and the company’s scientists, managers and laborers were every bit the heroes as the Toronto researchers. The new miracle drug to treat diabetes did not disappoint, since that time there have been even more advances and now have synthetic versions of insulin, so we are not as reliant on animal sources.
Diabetes mellitus is a condition that occurs when the body can not use glucose normally. Glucose is the main source of energy for the body’s cells. The levels of glucose in the blood are primarily controlled by the hormone called insulin which is made by the pancreas. In human patients, diabetes is classified as Type l or Type ll. Type l occurs when the pancreas does not make enough insulin, and Type ll occurs when the body can not respond normally to the amount of insulin made by the pancreas. Although diabetes in pets is sometimes classified as Type l or ll the difference between the types is less clear in pets than it is in humans.
Pets at risk of developing Diabetes are dogs average between 7-10 years but can occur at any age. Most diabetic cats are older than 6 years. Diabetes occurs in female dogs twice as often as male dogs and certain breeds maybe predisposed. Obesity is also a significant risk factor for the development of diabetes. Noticing the early signs of diabetes is the most important step in taking care of your pet. The earlier the diagnosis, the better the chance your pet may have for a longer and healthier life.
Early signs include:
• Excessive water drinking and increased urination
• Weight loss, even though there may be an increased appetite
• Decreased appetite
• Cloudy eyes (especially in dogs)
• Chronic or recurring infections (including skin infections and urinary infections)
m a fat boy now and I feel fine. I can climb a tree.

Dogs and cats with diabetes usually require lifelong treatment with special diets, a good fitness regimen and, particularly in dogs, daily insulin injections. The key to managing diabetic pets is to keep your pet’s blood sugar near normal levels and avoid too-high or too-low levels that can be life-threatening. A treatment that works for one pet might not work as well for another pet, and patience is important as you and your pet adjust to the new diet and medications.
Because older dogs and cats are more likely to develop age-related diseases or conditions, some of which could be confused with diabetes, regular examinations by a veterinarian can keep your pet healthy and detect problems before they become severe.
Diabetic dogs and cats can live long and healthy lives with proper management and veterinary care. If you notice any changes in your pet’s behavior or weight, consult your veterinarian. It is amazing how far we have come since the wonderful power of insulin was discovered. The future of insulin itself is not certain because better therapies could someday make obsolete the miracle drug of 1921.

Dr. Tessa Morgan

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