NINETY YEARS of InsUlIn – Canada celebrates

Transcription

NINETY YEARS of InsUlIn – Canada celebrates
Diabetes in soCiety
NINETY YEARS
of InsUlIn –
Canada celebrates
Marc Aras
The discovery of insulin in 1921 is undoubtedly one of the most
significant medical discoveries of the 20th century. frederick
Banting is considered as the main discoverer since he was the
one who had the idea of tying a ligature round the pancreatic
canals in order to provoke diabetes. when he was still a young
surgeon in London, ontario (Canada), he met JJr Macleod
of the University of Toronto and suggested experimenting
with this procedure in dogs. Not entirely convinced, professor
Macleod provided him with the necessary research laboratory
and offered the services of a young science student, Charles
Best. They started their experiments during the summer of
1921. The dogs indeed developed diabetes. The pair then tested
various pancreas extracts in order to – or so they hoped – cure
the diabetes. After numerous trials, they managed to stabilize
the glycaemia of one of their guinea pigs. Marc Aras takes up
the story of a truly great Canadian achievement.
Banting and Best showed their results
to Macleod and excitement began to
grow around their work. A young chemist, James Collip, was appointed to help
them prepare pancreas extracts. The
first articles from that research were
published at the end of 1921.
On the 11 January 1922, the first injection of an extract was given to 14-yearold insulin pioneer Leonard Thomson.
According to the doctor who gave him
that injection, the thick liquid was a
brownish colour, which clearly indicates the presence of other substances.
Analyses were carried the following day:
Leonard’s glycaemia dropped from 24.5
mmol/L to 17.8 mmol/L. A relatively
large amount of glucose was still passing
through his urine and this first trial was
considered a ‘semi-failure’.
Macleod and Collip were not aware of
the intentions of Banting and Best; they
were surprised and upset at having been
kept unaware of these developments.
Collip believed he could produce purer
insulin and told Banting and Best that
they should have waited before experimenting on people.
April 2012 • Volume 57 • Issue 1
DiabetesVoice 41
DIAbetes IN sOCIetY
The extract was then called ‘isletin’;
only in April 1922 did it receive
the familiar name insulin.
Only on 23 January, 12 days after the
first injection, Collip resumed the experimental treatment with Thomson.
This time, the success was complete;
his glycaemia dropped from 28.9 to
6.7mmol/L. Nearly no sugar is passed
through into the urine. Over the next
couple of days, when Leonard did not
receive any of the insulin extract, his glycaemia rose again. During the following
weeks, he received the daily injections
that helped him gain weight and recover
some strength.
In February 1922, six young people
with diabetes received insulin extract
with the same positive results. At that
time, the extract was then called ‘isletin’;
only in April 1922 did it receive its final,
now familiar, name – from the English
physiologist Sir Edward Albert SharpeySchafer. The breakthrough in February
had made the headlines. Macleod’s laboratory began preparing larger amounts
of insulin in response to overwhelming demands. The US-based Eli Lilly
Company was approached to produce
insulin in industrial quantities. In 1923,
insulin made from ox pancreas – and
later from pigs – was made available to
large numbers of people with diabetes.
At the end of 1923, Banting and Macleod
received the Nobel Prize for their discovery. They shared this Prize with their
two fellow researchers.
If Banting were working
today, at least 10 years
would be needed for
insulin to be approved.
Perhaps the most astonishing part of this
discovery is the speed with which they
moved from animal testing to commercialization. In comparison, if Banting were
working today, at least 10 years would be
needed for insulin to be approved! The
protocols for research and the consent
of people, like Leonard Thomson, undergoing an experiment are much stricter
nowadays, and must be passed by an ethics committee. The speedy processes of
yesteryear saved many lives.
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DiabetesVoice
Different types of insulin have since
been developed – the fast- and sloweracting insulins. In the 1970s, the first
human insulins were developed, not
from human pancreas but by chemical
manipulation of animal insulins and by
genetic engineering of yeast and bacteria.
Gene modification produced the rapidacting analogue insulin in the 1990s and
flatter long acting insulins a little later.
Research is still underway to develop
other types of insulins that might help
people achieve better control.
Today, more than
30 million people
worldwide live
thanks to insulin.
Last year, the first person to have lived
on insulin for 85 years was celebrated
in the USA. Bob Krause, a 90-year-old
retired engineer was born in the year
insulin was discovered!
The Bank of Canada announced on
World Diabetes Day, 14 November, 2011
the release of a new CAD100 bill made
of a special resistant material, commemorating the discovery of insulin.
The world-famous Canadian medical
achievement is portrayed on the reverse
of the bank note, where an insulin vial
illustrates that historic breakthrough.
marc Aras
Marc Aras is the communication
director of Diabète Québec.
April 2012 • Volume 57 • Issue 1