adrenaline

Adrenaline comes from Latin ad (near, upon) + rēnālis (of the kidneys), naming the adrenal glands that sit atop each kidney. The Japanese chemist Jōkichi Takamine isolated the active hormone in 1901 and patented it under the name 'Adrenalin' (without the 'e'). This was a brand name owned by Parke-Davis pharmaceutical company. Meanwhile, the American pharmacologist John Jacob Abel had independently isolated a similar substance and called it 'epinephrine' — from Greek epi (upon) + nephrós (kidney). Same meaning, different language.

The naming dispute was never fully resolved. In the United States, 'epinephrine' became the official pharmacological name, partly because 'Adrenalin' was trademarked. In Britain and most of the world, 'adrenaline' (with the 'e') became the standard generic term. The same molecule has two names divided by an ocean. American doctors say epinephrine. British doctors say adrenaline. The EpiPen is named for one. The 'adrenaline rush' is named for the other.

The hormone's effects were understood through Walter Bradford Cannon's research on the 'fight or flight' response in the 1910s and 1920s. Cannon demonstrated that the adrenal glands released adrenaline in response to threats, preparing the body for action: increased heart rate, dilated pupils, redirected blood flow from digestion to muscles. The phrase 'adrenaline rush' entered common speech by the mid-twentieth century, naming the sensation of sudden physical readiness.

Synthetic epinephrine/adrenaline is a life-saving drug for severe allergic reactions (anaphylaxis). The EpiPen auto-injector, developed in the 1970s, allows non-medical personnel to administer it. The EpiPen has also become a symbol of pharmaceutical pricing: Mylan raised the price from $100 to over $600 between 2007 and 2016, provoking congressional hearings. A hormone named for its location in the body became a flashpoint for American healthcare economics.