The Discovery of Insulin

	Insulin was first successfully given to a 14-year-old boy with diabetes in January 1922, in Toronto, Canada. They boy who was almost dead, quickly regained his strength. Further testing on other patients also proved successful.

	It’s discoverer, Dr. Federick Banting, and his professor, John Macleod were awarded the Nobel Prize in Physiology or Medicine in 1923, as news of the successful treatment spread about the continent. Banting and Macleod also shared their cash reward with a medical student and a biochemist, Charles Best and Bertram Collip.

	In October 1920, Banting, an unknown surgeon with a bachelor’s degree in medicine, thought that pancreatic digestive juices could be harmful to the secretions of the pancreas  produced by the islets of Langerhans, clusters of cells whos functions was to produce insulin -producing cells (which was unknown at the time). His plan was to tie the pancreatic ducts to stop the flow of enzymes to the pancreas, which would cause it to degenerate, and lose its ability to secrete the digestive juices. Then, the cells that were thought to produce an anti-diabetic secretions could be safely extracted from the pancreas.

	In early 1921, he took his idea to John Macleod, a professor at the university of   Toronto, who was also studying diabetes. The professor did not think that Banting’s ideas were true, however, he was conviced by Banting, and gave him a basic laboratory, and 10 dogs. This is also where his assistant, Charles Best joined him.

	The experiment started in the summer of 1921, by removing the pancreas of one of the dogs. This caused it to develop diabetes: becoming weaker, being unusually thirsty, and higher blood sugar levels. On another dog, they degenerated the pancreas by tying it off, removed it from the dog, sliced into small pieces, half frozen in a salt water mixture, ground up then filtered. This substance was named isletin. This substance was injected into the diabetic dog, which then fully recovered from diabetes.

	They then started using the pancreas of cows to gain more of the extract, which was then used to keep several more diabetic animals alive. These results then convinced Macleod to give them better funding, move them into a better laboratory, and suggested to call the substance insulin.

	Bertram Collip joined the project, and successfully managed to purifying the substance and find the correct dosage, making it ready for treating humans. This led them to successfully treat diabetes in 14-year-old Leonard Thompson, and other further volunteer diabetics. By 1923, the medical firm “Eli Lilly” was able to produce enough insulin to supply the whole continent of North America.