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Tuesday 25 August 2015

Insulin

Canadian physiologist Frederick Banting was inspired to research the treatment of diabetes while preparing a class lecture on the pancreas, when he read a paper about the relationship between the pancreas and diabetes. He knew it was an accepted fact that diabetes was caused by a disorder of the pancreas that kept the body from making use of sugar, so Banting decided that if he tied off the pancreatic duct he could isolate the hormone causing the disorder.

In the spring of 1921, Banting traveled to Toronto to explain his idea to J.J.R. Macleod, who was Professor of Physiology at the University of Toronto, and asked Macleod if he could use his lab space to test it out.  Macleod agreed and lent him Charles Best, a research student at the university.

After several months of experiments on laboratory dogs, Banting and Best prepared a solution containing the hormone insulin which they injected into the veins of a diabetic dog, and within a few hours the dog was walking again. Soon they were able to purify these extracts sufficiently to inject and treat diabetic patients.

Frederick Banting joined by Charles Best in office, 1924

At Toronto's General Hospital, 14-year-old diabetic Leonard Thompson became on January 11, 1922 the first person to be treated with the insulin drug, using a fetal calf pancreas extract. However, the ox extract was so impure, Thompson suffered a severe allergic reaction, and further injections were canceled. Biochemist James Collip, who was helping Banting and Best, worked day and night to improve the extract. A second dose was injected twelve days later, which was completely successful in completely eliminating the glycosuria sign of diabetes.

Frederick Banting, Charles Best, and James Collip agreed to receive $1 each in exchange for giving their patent rights for Insulin to the Board of Governors of the University of Toronto in 1923. The university then gave pharmaceuticals the rights to manufacture Insulin without royalties and to improve the formula in order to make the drug better and accessible to as many diabetics as possible at the lowest cost possible.

In 1923 Banting was jointly awarded the Nobel Prize for Medicine with his mentor John MacLeod, the Professor of Physiology at Toronto University. Banting, annoyed that Best was not mentioned, shared half of his prize with Best.

Banting, who received the Nobel Prize at age 32, remains the youngest Nobel laureate in the area of Physiology/Medicine.

Insulin

The word “Insulin” comes from the Latin for island, as it is produced by clusters of cells in the pancreas known as the Islets of Langerhans.

When the Japanese attacked Pearl Harbor in 1941 the Japanese occupation of China was tightened, and soon all the pharmacies in Shanghai were closed. Eva Saxl, a woman with type 1 diabetes, found herself with no legal access to insulin. She synthesised her own insulin in a basement saving not only her own life but the lives of over 200 people in the Shanghai Ghetto who would have died when legal insulin became unavailable.

The crystal structure of insulin in the solid state was determined by Dorothy Hodgkin; she was awarded the Nobel Prize in Chemistry in 1964.

Before the advent of biotechnology, the organisms used for insulin were the pigs and cows destined for our dinner plates—specifically, their pancreas glands, a waste product of the meatpacking industry.  In 1978 Genentech produce biosynthetic human insulin in Escherichia coli bacteria using recombinant DNA techniques.

Cone snail venom contains weaponized insulin. The insulin forms part of a poison mixture evocatively known as “nirvana cabal”. It allows the snail to disable entire schools of swimming fish by sending them into 2hypoglycaemic shock", a condition brought on by plummeting blood sugar levels.

Male platypus venom contains a hormone that promotes insulin release, called GLP-1; it's found in humans but degrades quickly. Platypuses make a long-lasting form of it, paving the way to new diabetes treatment; the platypus GLP-1 can be made in the lab so no platypuses will be needed for it.

Insulin is the sixth most expensive liquid in the world at $9,400 per gallon with prices expected to rise in the future.

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