John James Richard Macleod and Frederick Grant Banting are Awarded the Nobel Prize in Medicine for the Discovery of Insulin

Determined to investigate this possibility, Banting discussed it with various people, among whom was J.J.R. Macleod, Professor of Physiology at the University of Toronto, and Macleod gave him facilities for experimental work upon it.

Dr. Charles Best, then a medical student, was appointed as Banting's assistant, and together, Banting and Best started the work which was to lead to the discovery of insulin.

Macleod's main work was on carbohydrate metabolism and his efforts with Frederick Banting and Charles Best in the discovery of insulin used to treat diabetes. For this Banting and Macleod were jointly awarded the Nobel Prize for Medicine in 1923. Macleod was awarded half of the Nobel Prize for the discovery of insulin, even though many people (including Banting) publicly insisted that Macleod's involvement was minimal and Best's work had been essential. However, it was MacCleod's research plan and his suggestion to inject intravenous degenerated pancreas into depancreatinized dogs that ultimately led to the successful isolation of insulin. There is currently a controversy regarding the role of Banting and Best in attempting to 'write out' Macleod and his colleague James Collip from the history books. Macleod's receiving the Nobel Prize over Best was controversial at the time (see Nobel Prize controversies). He wrote eleven books, including Recent Advances in Physiology (1905); Diabetes: its Pathological Physiology (1925); and Carbohydrate Metabolism and Insulin. (1926)