Technology
A century of dramatic breakthroughs have led to the insulin therapy we are lucky to have access to today. Marlon Moala-Knox investigates.
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efore the discovery of insulin, type 1 diabetes was almost impossible to treat. Putting patients on strict diets might lengthen their life by a few years, but dying young was still the norm, and sometimes the diets themselves killed the patients – they were eating too little to survive. This was the reality for people with type 1 up until about 100 years ago, when production of insulin for medical use started. Before it could be used as a treatment, however, we first needed to know it existed. HOT ON THE TRAIL OF INSULIN
It was about 150 years ago that Western science began to figure out what that long organ behind the stomach – the pancreas – might be for. In 1869, German medical student Paul Langerhans was studying the pancreas when he noticed that, scattered
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DIABETES WELLNESS | Summer 2021
throughout it, were interesting clumps, or ‘islands’, of cells. Noone was sure what they did, but they were given the name ‘the islets of Langerhans’. Some researchers thought they might play a role in regulating digestion. So, in 1889, two German physicians, Oskar Minkowski and Joseph von Mering, surgically removed the pancreas of a healthy dog to see how it affected its digestion. What they discovered was that the dog immediately developed symptoms of diabetes. This was the first time a link was established between diabetes and the pancreas. From 1910, Sir Edward AlbertSharpey-Schafer, an English physiologist – sometimes regarded as the founder of endocrinology – began to theorise that the only thing missing from the pancreases of people with diabetes was a single hormone. He found that the islets of Langerhans made a chemical that metabolised glucose, and he named this ‘insulin’ after the Latin word for island: ‘insula’. However, attempts to extract insulin from the pancreas were unsuccessful. Enzymes from the pancreas kept destroying the insulin during the extraction process. That was, until 1921.
FIRST SUCCESSFUL INSULIN EXTRACTION
One hundred years ago, Canadian medical researcher Frederick Banting and his assistant Charles Best found a way to extract insulin by inducing atrophy (a kind of shrivelling) in a dog’s pancreas, while leaving the islets of Langerhans intact. Banting and Best then managed to keep a dog with diabetes alive for an extended period by injecting it with insulin extracted from a non-diabetic dog’s pancreas. Now that this method was proven to work, Banting and Best teamed up with their colleagues John Macleod and James Collip to develop the process further. Their goal was to extract insulin in a purer form, and in quantities large enough for practical use in diabetes treatment. INSULIN THERAPY TAKES OFF
It’s thought that the first human patient to be treated with insulin was Leonard Thomas, a 14-yearold boy with type 1 diabetes at Toronto General Hospital who was close to death. His first injection of insulin went wrong – impurities in the extract gave him an allergic reaction. However, after the researchers further refined their methods, and Thomas began
