John James Richard Macleod, the Nobel Prize winning Scottish physician and physiologist, was born on the 6th of September, 1876.
John James Richard Macleod will forever be associated with the discovery of insulin, the name he gave to the breakthrough treatment for diabetes that he and his team discovered in 1921 and for which he and Frederick Banting were awarded the 1923 Nobel Prize in Physiology or Medicine. You might get picky-picky and suggest that Macleod himself didn’t personally discover insulin, especially as he was back home in Scotland at the moment of discovery, but his was the inspiration and the direction that made it happen. During the early part of the 20th Century, Macleod made his name in medical research, initially collaborating with the physiologist Sir Leonard Hill on a study of caisson sickness, otherwise known as ‘the bends’, which is what deep sea divers experience if they rise too rapidly to the surface without gradual decompression. Early on, he also became interested in carbohydrate metabolism, particularly in relation to diabetes. He became a noted pioneer in diabetes research and built his reputation as an authority on that subject, delivering many important articles and lectures. He was much sought after and when he joined the University of Toronto, in 1918, as Professor of Physiology, they had held the post vacant on his behalf for two years.
During his career, Macleod published eleven books, including his major work, ‘Diabetes: Its Physiological Pathology’, and ‘Carbohydrate Metabolism and Insulin’. He also produced a standard textbook ‘Physiology and Biochemistry in Modern Medicine’, which placed increased emphasis on the importance of chemistry in physiology and eventually became a classroom standard and went through seven editions before his death. Shortly before his team began the research that would lead to the discovery of insulin, Macleod delivered an important paper, ‘Methods of Study of Early Diabetes’, to the May 1921 symposium of the Ontario Medical Association. That same year, Macleod was appointed President of the American Physiological Society and his other honours included becoming a Fellow of the Royal Societies of Canada, London and Edinburgh, in addition to that of the Royal College of Physicians, in London. He was also a member of the League of Nations health committee. Macleod’s subsequent work and publications involved a variety of physiological and biochemical topics, including carbamates, the purine metabolism, the breakdown of liver glycogen, hyperglycemia, intracranial circulation, ventilation, and surgical shock.
John James Richard Macleod was born on the 6th of September, 1876, in Clunie, near Dunkeld in Perthshire. When his family moved to Aberdeen, Macleod went to the Grammar School and later entered Marischal College at the University of Aberdeen to study medicine. In 1898, he graduated with an honorable distinction, earning an M. B. and Ch. B., and was awarded the Anderson Traveling Fellowship. In 1899, thanks to that scholarship, he attended the Institute for Physiology at the University of Leipzig, where he studied physiological chemistry for a year. The following year, at the turn of the Century, he was made Demonstrator of Physiology at the London Hospital Medical School and, in 1902, was given the position of Lecturer in Biochemistry and granted the McKinnon Research Studentship of the Royal Society of Medicine. It was during his time in London that he worked with Sir Leonard Hill on caisson sickness. Macleod's work and reputation had attracted the notice of officials at Western Reserve University in Cleveland, Ohio, and they offered him the position of Professor of Physiology. So in August, 1903, Macleod sailed off to the United States of America and it was whilst in Ohio that he became interested in carbohydrate metabolism. Then, in 1918, Macleod was elected Professor of Physiology at the University of Toronto, where he was also made Director of the Physiological Laboratory and Associate Dean of the Faculty of Medicine. He had been offered the position two years previously, but had been unable to take it at that time. The University was so keen to obtain his services that the position was left open until Macleod was able to accept.
It was Macleod’s reputation that drew Frederick G. Banting to Toronto and into history. Macleod had come to believe that the pancreas was involved in diabetes, but he had been unable to discover exactly how. Neither had the research team of Sharpey-Schafer, which had suggested as early as 1916 that the pancreas produced an internal secretion that controlled the metabolism of sugar. Those scientists had named the hypothetical substance ‘insuline’. Banting came to Macleod with an idea that he could isolate and extract the pancreatic hormone and Macleod ultimately set up a laboratory team with that objective. The research team of Banting, Charles H. Best, James Bertram Collip and Macleod were able to prove the link between diabetes mellitus and the failure of the pancreas to produce the secretion. Not only that, by January, 1922, these amazing guys were able to successfully extract what Macleod called ‘insulin’ and prove its miraculous efficacy on a fourteen years old diabetic boy.
The discovery was publicly announced in February, 1922, but the next step was to refine methods of extracting and purifying the insulin for which Macleod sought the aid of the Connaught Anti-Toxin Laboratories. Eventually, as the researchers didn’t have the facilities to mass-produce insulin, the pharmaceutical manufacturer, Eli Lilly and Company, based in Indianapolis, became the first large scale producers of insulin. Macleod was also responsible for coordinating the patenting of insulin in Great Britain and the United States. However, all financial proceeds from the patent were given to the British Medical Research Council for the Encouragement of Research. None of Macleod’s team gained any profit from their discovery, but when Macleod and Banting were awarded the 1923 Nobel Prize, they shared the prize money with Best and Collip. Note that insulin does not cure diabetes; it does, however, improve management of the condition to prevent diabetic coma. It has been rightly hailed as one of the most important medical discoveries of the 20th Century.
John James Richard Macleod returned to Aberdeen in 1928, where he died on the 16th of March, 1935.