Narrowing of the airway tubes causes the symptoms of asthma. Today, all asthmatics should have with them the reliever medication Ventolin – this opens the airway tubes and improves breathing. Ventolin was discovered by the British pharmaceutical company Allen and Hanburys (now Glaxo Smith Kline) around 1969. The origins of this medicine begin though in the Victorian era.
Eating extracts of bovine adrenal gland was a health supplement in the Victorian era and, in 1900, Dr Solomon Solis-Cohen reported on the benefits of taking adrenal gland extracts for asthma. Patients with asthma noted that their breathing improved after taking this extract for a few weeks. In 1901 Jokichi Takamine isolated a substance from the adrenal gland, which was called adrenaline. Asthmatics inhaled it and bingo they could breath more easily! Adrenaline is quick to act but the effects wear of quickly thus patients took many inhalations – often all at once. Very soon warning signs were appearing of side effects and fatalities due to taking adrenaline for asthma.
The question was now to make adrenaline safer – but how? It took about 60 years to figure this out. Adrenaline was shown to constrict blood vessels, open the airways and make the heart beat faster and they did this by acting at different receptors in these tissues. Constriction of blood vessels is caused by the alpha receptor, increases in heart rate by beta 1 and opening of airways by beta 2 receptors.
So now the race was on – could scientists modify the structure of adrenaline so that it acted on beta 2 but not beta 1 or alpha receptors – if so they would have a much safer and effective drug. Allen and Hanburys won this race and in 1969 they launched Ventolin a drug which acted at the beta 2 receptor but not alpha or beta 1. This drug revolutionised the treatment of asthma and almost 50 years later it is still the drug of choice to improve breathing in asthmatics.
Impeccable science but it was all a mistake (though lucky for asthmatics). Adrenaline is not absorbed from the stomach or small intestines – so it couldn’t have been adrenaline that was improving breathing following eating of adrenal gland extracts.
What was then? Today we know that it was a steroid similar to cortisol that was improving the symptoms of asthma for the Victorians – it is absorbed from the gut. Nothing was known about steroids in this era. Cortisol is anti-inflammatory and improves breathing in asthmatics by reducing inflammation and swelling of the airways. Today, inhaled anti-inflammatory steroids (based on cortisol) are prescribed to treat asthma. They take many days to weeks to achieve maximum effect (something which the Victorians noted).
Thus, the Victorians penchant for eating adrenal gland extracts inadvertently paved the way for the invention of our modern drugs to treat asthma – sometimes you need a lucky break in science!
Michael Trevethick is a biologist who has studied at Cambridge University, the University of Virginia and worked for Glaxo Smith Kline and then Pfizer. Mike was asked to run projects on Asthma and it was while Mike was preparing lectures for university students on basic asthma therapy that his interest in the history of the disease began.
Mike has run courses for Thanet U3A and the U3A Science Network on the history and science of medicines and key milestones in the advancement of science.
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