Otto Loewi Biography (1873-1961)
- pharmacologist, physiologist
Otto Loewi (pronounced l-ee) was born in Frankfurt am Main, Germany, on June 3, 1873. On the advice of his parents, Loewi entered the University ofStrasbourg to study medicine, and received his medical degree in 1896. Aftergraduation, he briefly visited Italy, and then returned to Germany for moretraining in chemistry and experimental methods. During this period, he also worked in the tuberculosis and pneumonia wards at the City Hospital ofFrankfurt, where he was discouraged from continuing with clinical medicine because of high death rates. Instead, he turned his attention to an academic career in scientific research, and in 1898 he joined the department of pharmacology at the University of Marburg, first with an assistantship and then as alecturer.
By 1902, Loewi had published the results of his scientific research at Marburg. His work dealt with the functioning of the kidneys and the effects on these organs of substances that increase the production of urine, known as diuretics. In 1903, along with other researchers including Henry HallettDale, Loewi began to consider the chemical transmission of nerve impulses. The hormone adrenaline and the chemical muscarine had already been identified as possible nerve transmitters by several English physiologists. In 1905,Loewi followed Hans Meyer, under whom he had worked at Marburg, to the University of Vienna. The same year, he met Gulda Goldschmiedt, the daughter of a chemistry professor, in Switzerland, and he married her the following year. They would have four children.
At the University of Vienna, Loewi concentrated on the effects of adrenalineand noradrenaline on diabetes and blood pressure. He also studied the response of the heart to the stimulation of the vagus nerve, one of the main cranialnerves in the autonomic system. In 1909, he was appointed to the Universityof Graz as a professor of pharmacology, where he remained until the German occupation of Austria in 1938.
By 1921, fifteen years after the idea of chemical transmission of nerve impulses had first been proposed by the English physiologists, scientists had still not discovered definite evidence of the existence of a chemical transmitterwithin the nervous system. One night Loewi had a dream that would help; he dreamed the design of an experiment that would determine the existence of a chemical transmitter. He jotted down some notes from the dream, still half asleep, but when he awoke the next morning he could not read his scrawl. The nextnight at three o'clock the idea returned to him; this time he immediately went to his laboratory.
For this pathbreaking experiment, Loewi used two hearts from frogs. He removed the vagus nerve from the first heart, and he stimulated the same nerve in the second one. After stimulating the nerve in the second heart, he removed some fluid and injected it into the heart without the vagus nerve. He observedthat the rate of this heart slowed as if the vagus nerve had been stimulated.Then he stimulated the heart with the vagus nerve so it would beat faster. He again removed fluid and injected it into the heart without the vagus nerve.Its rate increased as if it had been stimulated directly by the missing nerve.
Loewi had established the role chemicals play in the transmission of nerve impulses, but he was not sure at first what these chemicals were. He called one"vagus substance" and the other "accelerator substance." Over the next fifteen years, Loewi, along with his colleagues, published a number of papers on the results of his initial experiment. What he had called vagus substance wasidentified as acetylcholine in 1926; other transmitters were later identified. In 1936, Loewi identified adrenaline as one of the sympathetic nervous system transmitters and noradrenaline as the most important one. Henry Hallett Dale shared the 1936 Nobel Prize with Loewi for his discovery of chemical transmitters in the voluntary nervous system.
After the German occupation of Austria in 1938, Loewi was only allowed to leave because he turned over his Nobel Prize money to the Nazis. His family wasalso able to escape, and they joined him in New York City in 1940. He becamea United States citizen in 1946. He spent the rest of his life writing articles, delivering lectures, and writing his memoirs. He died on December 25, 1961, at the age of 88 in New York City.