Otto Loewi

Otto Loewi (June 3, 1873 - December 25, 1961) was a German-American pharmacologist.

Loewi was born in Frankfurt, Germany. He later spent many years in Austria, where he investigated how vital organs respond to chemical and electrical stimulation. He also established their relative dependence on some kind of proteins for proper function. Consequently, he learnt the way of how nerve impulses are transmitted by chemical messengers. The first chemical neurotransmitter that he identified was acetylcholine.

According to Loewi, the idea for his key experiment came to him in his sleep. The next day, he dissected out of frogs two beating hearts: one with the vagus nerve which controls heartrate attached, the other heart on its own. Both hearts were bathed in a saline solution (i.e. Ringer's solution). By electrically stimulating the vagus nerve, Loewi made the first heart beat faster. Then, Loewi took some of the liquid bathing the first heart and applied it to the second heart. The application of the liquid made the second heart also beat faster, proving that some soluable chemical released by the vagus nerve was controlling the heartrate. He called the unknown chemical Vagusstuff. It was later found that this chemical corresponded to acetylcholine.

His discoveries helped in enhancing medical therapy and personally earned for him the 1936 Nobel Prize in Physiology or Medicine which he shared with Sir Henry Dale.

Otto Loewi's investigations “On an augmentation of adrenaline release by cocain” and “On the connection between digitalis and the action of calcium” were profound concepts and were studied relentlessly by others decades later.

He also clarified two mechanisms of eminent therapeutic importance: the blockade and the augmentation of nerve action by certain drugs.

Loewi moved to the United States in 1940, where he became a research professor at the New York University College of Medicine. He died in New York City.