1. In Latin “insula” means an Island.
2. In 1868 Paul Langerhans of Germany working on the structure of Pancreas found Islets of Langerhans specialised cells richly supplied with blood vessel.
3. But the function of pancreas remained unknown.
4. Many others interested in the function of pancreas found that its removal from the body of an experimental animal would lead to the development of disease called ‘sugar diabetes’ (or) diabetes mellitus.
5. Diabetes is a condition in which the amount of free sugar in the blood and in the urine is abnormally high.
6. Later scientists found that when they tied the pancreatic duct that emerge from the duodenum caused the degeneration of pancreas but not Islets of Langerhans.
7. Moreover the animal would not develop diabetes. This was really a strong evidence that the level of blood sugar is linked with the Islet cells.
8. By 1912 workers were convinced that the Islets produced a secretion which directly liberated into the blood.
9. Ten years later in Toronto, Banting, Best and Macleod finally succeeded in extracting insulin from degenerate animal pancreas whose ducts to the intestine had been tied.
10. Insulin is now produced in large quantities for the treatment of human sufferers diabetes, to whom it is administered by injection into the skin.