History of Insulin Discovery
Diabetes was once a life-threatening, untreatable disease. Knowing that sugar can worsen the condition, diabetic patients were put on a harsh diet that restricts sugar intake (to the point that some of them died of starvation). While prolonging their life expectancy by a few years, strict diets never saved the patients.
The discovery of insulin
The discovery of insulin can be traced all the way back to the nineteenth century when diabetic patients were found to have a damaged pancreas. In 1869, Paul Langerhans (a medical student from Berlin, Germany) discovered a cluster of cells within the pancreatic tissue. These cells were later named the Islets of Langerhans in honor of the discoverer. In 1889, Joseph von Mering and Oskar Minkowski conducted an animal experiment in which pancreas removal was found to cause diabetes. This indicated that pancreas is involved in the production of a glucose-regulating substance. Similarly, in 1901, Eugene Opie discovered that the Islets of Langerhans play a role in the synthesis of insulin. He also observed that the destruction of Islets of Langerhans can lead to diabetes.
In 1921, a series of animal experiments were performed by Charles Best and Dr Frederick Banting. Consistent with previous studies, the removal of pancreas was found to induce diabetic symptoms in dogs. The dogs were then administered with an injectable containing a pancreatic extract, which helped to keep them alive. Best and Banting began to source pancreases from cows, as they needed a larger supply of organs for further testing. Knowing that they were onto something big, Macleod increased the funding and offered them a proper laboratory. He also named the extract as insulin. Eager to test on humans, Best and Banting injected themselves with the extract. While generally unharmed, they experienced signs of hypoglycemia such as weakness and dizziness. Bertram Collip, a biochemist who later joined the team, helped purify the insulin and find the correct dosage. He also learned to counter the hypoglycemic effects of an insulin overdose using glucose. Leonard Thompson was the first patient to use insulin, which helped him to live for another 13 years. It was a considerable achievement, considering the fact that diabetes patients at the time often lived for months under starvation diets.
The advancement of insulin
In 1922, Eli Lilly became the first manufacturer of insulin. Macleod and Banting received a Nobel Prize a year later.
The advancement of insulin continues long after the breakthrough in diabetes treatment. In the 50s, an intermediate-acting insulin was introduced by Novo Nordisk, a pharmaceutical company based in Denmark. Frederick Sanger was awarded the prestigious Nobel Prize in Chemistry in 1955 for his work on insulin sequencing. In 1963, the full chemical synthesis of insulin was made possible.