The Discovery of Adrenaline 1893 – Its Importance in Bodily Functions

Adrenaline's discovery is noteworthy because it marked the first laboratory production of a hormone secreted by a gland. 

Hormones are substances released by a cell in one part of the body that affect other cells, acting as “chemical messengers".

British physician George Oliver and British physiologist Edward Sharpey-Schafer began their first systematic studies of adrenaline's effects in 1893. Dr Oliver experimented by giving extracts of the adrenal glands (located above the kidneys) to his son. After observing changes in the diameter of his son's blood vessels, Oliver suggested that Sharpey-Schafer inject the extract into a dog. Surprisingly, a mercury blood pressure instrument showed a very dramatic change in the dog's blood pressure. The pair showed that the active substance of the adrenal glands, now known as adrenaline or epinephrine, affected the constriction of arterioles (small-diameter blood vessels), thereby increasing blood pressure. 

Anatomist Stephen Carmichael commented on these developments: 

"Their publications reporting their observations in 1894 represent the first demonstration of a hormonal effect. Many historians believe that this work on the adrenal medulla (the centre of the adrenal gland) was a turning point in endocrinology.”

Japanese chemist and samurai Jokichi Takamine is considered the first person to isolate and substantially purify adrenaline. Although his assistant actually obtained the first crystalline product, Takamine became wealthy through his patent covering the principle of raising blood pressure. Adrenaline began to be used in bleeding control, cardiology, obstetrics and allergy treatment.

Adrenaline is vital to normal bodily functions. 

• It is released in greater quantities during stress and increases the heart rate, increasing the volume of blood pumped from the heart chambers with each beat. 
• This increases blood flow to the muscles. 
• Adrenaline also relaxes smooth muscle in the airways and constricts peripheral arteries and vessels far from the heart. 
• Attention is recommended to adrenaline-related dilation of blood vessels (vasodilation) in the muscles, liver and heart.

Description of the article image: Adrenaline is made from the amino acids phenylalanine and tyrosine produced by the adrenal glands (the muted orange organs shown above the kidneys). George Oliver is on the left of the image and Edward Albert Sharpey-Schafer on the right. The adrenaline molecule is in the centre of the image.

Historical figures mentioned in the article: George Oliver (1841–1915), Edward Albert Sharpey-Schafer (born Schäfer; 1850–1935), Jokichi Takamine (1854–1922)

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