The Internal Secretion of the Pancreas

Summary

'The Internal Secretion of the Pancreas' is the first scientific paper describing the work at the University of Toronto that led to insulin. Frederick Banting and Charles Best presented their results to a physiological society in Toronto in late 1921, and the paper was published in the Journal of Laboratory and Clinical Medicine in February 1922. Diabetes mellitus was then a fatal disease for most children and young adults who developed it. Patients wasted away despite near-starvation diets. Scientists knew that removing the pancreas from a dog caused diabetes and suspected that small clusters of cells in the pancreas, the islets of Langerhans, produced a substance that controlled blood sugar. Attempts to extract it had failed, perhaps because digestive enzymes from the rest of the pancreas destroyed it. Banting's idea was to tie off the pancreatic ducts of dogs so that the cells producing digestive juices would waste away while the islets survived. In the summer of 1921, working in the laboratory of Professor J. J. R. Macleod, Banting and Best prepared extracts from such degenerated pancreases and injected them into dogs whose pancreases had been removed. The paper reports that the extracts lowered blood sugar and reduced the sugar in the urine, and that the dogs' condition improved. They called the active substance 'isletin'. They later found that extracts of whole fetal calf pancreas also worked. The paper is a careful laboratory report, with charts of blood sugar after injections. It was quickly followed by a second paper, in March 1922, describing the first treatment of human patients, including the fourteen-year-old Leonard Thompson, with a purer extract prepared by James Collip. The substance, renamed insulin, was being produced commercially within a year. The discovery transformed diabetes from a death sentence into a manageable condition and won Banting and Macleod the Nobel Prize in 1923.

Top Lessons

• An idea tested

  Banting's idea came from reading a medical article late at night. Turning it into a result took a summer of hard laboratory work.

• Teamwork and credit

  Banting, Best, Macleod and Collip each contributed, and arguments over credit were bitter. Discoveries rarely belong to one person.

• Animals in research

  The work depended on experiments on dogs, many of which died. Medical progress raises questions about our duties to animals.

• For the Christian reader

  The discoverers sold the patent to the University of Toronto for a token sum so that insulin could be made widely. Christians can see in this a picture of knowledge used for the good of others, and in the healing of dying children an echo of Christ's compassion.

Verified Quotes

Medical Lens

The first report of the Toronto experiments that led to insulin.

• Experiments

  Extracts from degenerated pancreas lower blood sugar in diabetic dogs.