On January 11, 1922 insulin was used for the first time on a human patient. Leonard Thompson, a 14-year-old diabetic at Toronto General Hospital, survived his previous death sentence of diabetes for another 13 years using insulin until he died from pneumonia at age 27.
In the nineteenth century, Paul Langerhans, a German pathologist (1847 – 1888) observed that patients who died of diabetes often showed a damaged pancreas. He also found some unknown clusters of cells in digestive juices. These cells were later identified as insulin-producing beta cells and, in his honor, were named islets of Langerhans.
In 1921 Frederick Banting, an unknown surgeon with a bachelor’s degree, had an idea about the islets in the treatment of diabetes. He took his idea to John Macleod, a leading figure in the study of diabetes. He convinced Macloed to finance his experiments and give him a laboratory. The isolation of the islets proved surprisingly effective on test animals. The substance was called isletin, later shortened to insulin.
Banting (Canada) and Macleod (Scotland) shared the 1923 Nobel Prize in Medicine for the development and safe use of insulin.