How We Discovered Heparin
A story about how a curious medical student went on to develop one of the most used 100 years ago
Medicine has come to the place where it is not not just because of science and research, sometimes it’s just about luck, observing and just being at the right place at the write time.
There are countless stories like this told about medical schools about how luck, observation and specially how medical students helped to change the course of medicine which for medical students is like folklore.
Some of these stories may be true, some may be myths but none of the less still fascinating.
One story that I’m telling today is about how we discovered heparin, which is used at hospitals everyday. It is a drug that prevents our blood from clotting. This prevents people at risk of developing strokes, heart attack and keep people safe.
The story
Heparin was discovered by Jay McLean and William Henry Howell. McLean was a second year medical student at Johns Hopkins University. He was working as a research assistant to Howell in 1916.
The pair was carrying researches about pro-coagulant preparations, which means they were looking for substances in the blood that made blood clot. And anticoagulation was not their field of interest.
Although not we know about mechanisms of blood clotting at 1916 medicine was still in it's early days.
McLean was stirpped of cash and was finiding it difficult to pay his rent and expenses at medical college.
So back to the story, McLean was interested about what prevents the blood from clotting while it is in the circulation. He tested various preparations extracted from different parts of the body trying to find out the substance that prevented blood from clotting.
One day he found out that one preparation that he made from liver extracts prevented the blood in the beaker from clotting which it was put.
He tested and retested to make sure that he didn’t make any mistake and it was evident that there was something that is made in the liver which prevented our blood from clotting within the circulation.
Because it was not a problem that his master was working on he did not mention about his findings to Howell at first, but after sometime he told his professor about what he as found.
As many other professors he did not believe that this medical student has found a natural anticoagulant. And there was no other way to convince his professor to believe what he has discovered.
So what young McLean did was he took a beaker, and collected blood from a cat to the beaker. Put the liver extracts that he found to the blood and kept the beaker on the his professor's desk and told him to call him back when this blood in the beaker clot. And he never called. The blood did not clot.
Now that his professor is convinced about what his student has discovered in the years to come both of them worked together to develop what McLean has discovered in the liver extracts to make it even better. In May 1935 first human trials were performed on heparin and was later declared safe to be used on humans.
Heparin is one of the most oldest still used in practice everyday. And the doctors in the generations to come developed it even further what we call enoxaparin — the low molecular weight heparin.
McLean later wrote about the difficulties that he faced in his life and what motivated him to achieve this.
THE DISCOVERY of heparin came as a result of my determination to accomplish something by my own ability.
I was reared without a father, and a child knows when there is no breadwinner to rely upon. My stepfather was unsympathetic to my plans for a medical education at Johns Hopkins. The earthquake and fire in San Francisco in 1906 stripped us of all accumulated assets; our house burned, my stepfather ‘s place of employment burned, and the outlook was stark.
Despite these handicaps, I made the decision to become a physician during my last year at Lowell High School in San Francisco (1908–1909).
It is a fascinating story about how a curious medical student, questioning his professor and through many difficulties in life went on to achieve greatness. This is one just one story being told at medical college and inspire medical students to go on and do great things.
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