So, 90 years (and a few days) ago they managed to treat their first Diabetic patient with Insulin. Excellent! In honour of this I am not going to write very much myself but rather quote some other, more intelligent, people.
I thought it might be a good time to look in to how the discovery of insulin was made so here is a complete rip off from Wikipedia for those of you that can’t be bothered to type insulin in to the Wikipedia search:
An article Frederick Banting read about the pancreas peaked his interest in diabetes. Research by Naunyn, Minkowski, Opie, Schafer, and others suggested that diabetes resulted from a lack of a protein hormone secreted by the Islets of Langerhans in the pancreas. Schafer had named this hormone insulin. Insulin was thought to control the metabolism of sugar; its lack led to an increase of sugar in the blood which was then excreted in urine. Attempts to increase the supply of insulin in patients were unsuccessful, likely because of the destruction of the insulin by the proteolyticenzyme of the pancreas. The challenge was to find a way to extract insulin from the pancreas prior to it being destroyed.
Moses Barron published an article on experimental closure of the pancreatic duct by ligature which further influenced Banting’s thinking. The procedure caused deterioration of the cells of the pancreas which secrete trypsin but left the Islets of Langerhans intact. Banting realized that this procedure would destroy the trypsin-secreting cells but not the insulin. Once the trypsin-secreting cells had died, insulin could be extracted from the Islets of Langerhans. Banting discussed this approach with J. J. R. Macleod, Professor of Physiology at the University of Toronto. Macleod provided experimental facilities and the assistance of one of his students, Dr. Charles Best. Banting and Best began the production of insulin—already discovered in 1916 by Romanian physiologist Nicolae Paulescu—by this means.
(Stop reading now if you’re squeamish!!!)
This is quoted directly from the Nobel Prize website:
In October 1920 in Toronto, Canada, Dr. Frederick Banting, an unknown surgeon with a bachelor’s degree in medicine, had the idea that the pancreatic digestive juices could be harmful to the secretion of the pancreas produced by the islets of Langerhans.
Banting, right, and Best, left, with one of the diabetic dogs used in experiments with insulin.
Credits: University of Toronto Archives
He therefore wanted to ligate the pancreatic ducts in order to stop the flow of nourishment to the pancreas. This would cause the pancreas to degenerate, making it shrink and lose its ability to secrete the digestive juices. The cells thought to produce an antidiabetic secretion could then be extracted from the pancreas without being harmed.
Early in 1921, Banting took his idea to Professor John Macleod at the University of Toronto, who was a leading figure in the study of diabetes in Canada. Macleod didn’t think much of Banting’s theories. Despite this, Banting managed to convince him that his idea was worth trying. Macleod gave Banting a laboratory with a minimum of equipment and ten dogs. Banting also got an assistant, a medical student by the name of Charles Best. The experiment was set to start in the summer of 1921.
The Experiment Begins
Banting and Best began their experiments by removing the pancreas from a dog. This resulted in the following:
- It’s blood sugar rose.
- It became thirsty, drank lots of water, and urinated more often.
- It became weaker and weaker.
The dog had developed diabetes.
Banting’s and Best’s laboratory, where insulin was discovered.
Credits: University of Toronto Archives
Experimenting on another dog, Banting and Best surgically ligated the pancreas, stopping the flow of nourishment, so that the pancreas degenerated.
After a while, they removed the pancreas, sliced it up, and froze the pieces in a mixture of water and salts. When the pieces were half frozen, they were ground up and filtered. The isolated substance was named “isletin.”
The extract was injected into the diabetic dog. Its blood glucose level dropped, and it seemed healthier and stronger. By giving the diabetic dog a few injections a day, Banting and Best could keep it healthy and free of symptoms.
Banting and Best showed their result to Macleod, who was impressed, but he wanted more tests to prove that their pancreatic extract really worked.
The new results convinced Macleod that they were onto something big. He gave them more funds and moved them to a better laboratory with proper working conditions. He also suggested they should call their extract “insulin.” Now, the work proceeded rapidly.
For the increased testing, Banting and Best realized that they required a larger supply of organs than their dogs could provide, and they started using pancreases from cattle. With this new source, they managed to produce enough extract to keep several diabetic dogs alive.
In late 1921, a third person, biochemist Bertram Collip, joined the team. Collip was given the task of trying to purify the insulin so that it would be clean enough for testing on humans.
During the intensified testing, the team also realized that the process of shrinking the pancreases had been unnecessary. Using whole fresh pancreases from adult animals worked just as well.
So apparently it was a fairly gruesome bunch of experiments that gave all of us Type 1 Diabetics our lifeline!
Of course science has moved on a lot in the intervening years, for one thing most insulin is synthetic now and cultured in labs rather than being harvested from animals, thankfully most of the changes have brought enormous leaps in understanding and control for those of us sans-insulin. As the saying goes things can only get better!