Euler, Ulf Svante von (1905-1983) was a Swedish physiologist who shared the 1970 Nobel Prize in physiology or medicine with British physiologist Sir Bernard Katz and American biochemist Julius Axelrod. Euler's work concerned the activation and storage mechanisms of neurotransmitters, chemicals that stimulate nerve or muscle cells.

Euler was born on Feb. 7, 1905, in Stockholm, Sweden. His father, Hans Karl August Simon von Euler-Chelpin, was a co-winner of the 1929 Nobel Prize in chemistry. His mother, Astrid Cleve von Euler, was a professor of botany and the daughter of the chemist who discovered the elements thulium and holmium. In 1922, Euler began medical school at the Karolinska Institute in Stockholm. He received his medical degree in 1930 Following graduation. he went to London to work with Henry Hallett Dale, who later shared the 1936 Nobel Prize in physiology or medicine for discoveries relating to the chemical transmission of nerve impulses. Euler returned to the Karolinska Institute and became an assistant professor of pharmacology and physiology. He was named chairman and professor of physiology in 1939 and remained there until his retirement in 1971.

Euler made many important discoveries in his career. In 1931, while studying in London, he isolated the substance that regulates muscle activity in the intestines. Then, in 1935, he identified a substance—which he mistakenly believed originated in the prostate gland—that lowered blood pressure and contracted muscle. He called this potent chemical prostaglandin. Eventually, researchers isolated many types of prostaglandins and discovered how to manufacture synthetic ones, which have had many important medical uses.

Euler devoted much of his research to the study of the neurotransmitter noradrenaline, also called norepinephrine, which controls automatic actions in the body, such as the body's response to stress. Euler made the connection between noradrenline and the sympathetic nervous system.

He died on March 10, 1983.