German-born US biochemist who carried out research into the metabolic processes involved
in the action of muscles. For this work he shared the 1922 Nobel Prize for Physiology or
Meyerhof was born in Hanover and studied at a number of German universities. From 1912 he
worked at the University of Kiel, becoming professor 1918. He headed a department specially
created for him at the Kaiser Wilhelm Institute for Biology in Berlin 1924-29, when he
moved to Heidelberg. As a result of Adolf Hitler's rise to power in the 1930s, Meyerhof
left Germany 1938 and went to Paris, where he became director of research at the Institut
de Biologie Physiochimique. In 1940, when France fell to Germany in the early part of World
War II, he fled to the USA, and was given a professorship at the University of
In 1920 Meyerhof showed that, in anaerobic conditions, the amounts of glycogen metabolized
and of lactic acid produced in a contracting muscle are proportional to the tension in the
muscle. He also demonstrated that 20-25% of the lactic acid is oxidized during the muscle's
recovery period and that energy produced by this oxidation is used to convert the remainder of
the lactic acid back to glycogen. Meyerhof introduced the term glycolysis to describe the
anaerobic degradation of glycogen to lactic acid, and showed the cyclic nature of energy
transformations in living cells. The complete metabolic pathway of glycolysis is known as
the Embden-Meyerhof pathway after Meyerhof and Gustav George Embden (1874-1933).
The Beginning of Meyerhof's Career in Science in detail
Ludolf von Krehl was building up a small research program on metabolism at his University
of Heidelberg Medical Clinic at the same time that Otto Meyerhof was finishing up his
medical studies in Heidelberg. Otto Warburg, who had been a student of Emil Fischer, had
joined Krehl in 1906. When Krehl offered Meyerhof his first research position in 1909, it
was Warburg's responsibility to teach the newly graduated physician his techniques for
investigations of respiration, oxygen consumption and growth rates in sea urchin eggs.
Warburg's innovative ideas and dynamic, self-confident approach had a dramatic impact on
Meyerhof, inspiring him to focus his career on physiological chemistry. Meyerhof worked
at Krehl's laboratory for little over two years, but the establishment of ties with Krehl
and the development of his close friendship with Warburg were to be factors which would
continue to shape Meyerhof's career.
After leaving Heidelberg, Meyerhof took a position at the University of Kiel, where he
quickly began to make a name for himself. In 1913, he presented an epoch making lecture
on the energetics of living cells. This was one of the very first adaptations of the
physical laws of thermodynamics to physiological chemistry. Meyerhof's goal was to
understand how energy is transformed during chemical interactions in the cell. He
recognized that between initial energy input via food and its final dissipation as
heat, a series of intermediate steps to transform that energy must occur to maintain
the organism in a state of dynamic equilibrium. With minor revisions, his theory on the
thermodynamics of living matter remained influential for decades.
In his ensuing efforts to relate energy transformations and chemical changes to
cellular function, Meyerhof turned his attention increasingly toward experimentation
with muscle, where such transformations promised to be large enough in scale to test
his new theory. Meyerhof, however, was also interested in analogies between oxygen
respiration in muscle and alcoholic fermentation in yeast and the role that enzymes
played in both. 1918 marked the first experimental milestone in Meyerhof's career,
when he showed that a coenzyme involved in the production of lactic acid in muscle
was the same as Harden and Young's coenzyme in alcoholic fermentation in yeast. This
was important early evidence of the unity in life of fundamental biological processes.
In his 1913 address, Meyerhof had mentioned the work of the Englishman, A.V. Hill.
Hill had pioneered methods to measure heat production in biological processes. Since
Meyerhof's lecture, Hill had found a pattern of discrete temperature changes during
muscle contraction and relaxation that suggested a complicated series of biochemical
interactions. This reminded him of work by Fletcher and Hopkins in 1907, which had
shown that lactic acid increases in resting muscle in an oxygen-free environment, but
then disappears when oxygen is reintroduced. Hill noted that his own measurements of
heat during anaerobic conditions correlated strikingly to Fletcher's and Hopkins' results.
This was important evidence for the theory that lactic acid was not simply a by-product of
muscle activity, but must be a part of the muscle machine itself.
Soon after the end of World War One, Meyerhof began collaborating with A.V. Hill.
Both men were convinced that a key to understanding metabolism lies in quantitatively
correlating data on heat development, mechanical work and cellular chemical reactions.
In Germany, Meyerhof focused on chemical methods to measure oxygen consumption, the
conversion of carbohydrates, lactic acid formation and decomposition, then correlating
it to thermodynamic data and various phases of muscle activity.
Meyerhof at the the time of the award of his Nobel Prize
Between 1918 and 1922, Meyerhof worked out an extraordinary amount of this biochemical
detail, including proofs that it is glycogen that is converted into lactic acid in the
absence of oxygen. He also showed that in the presence of oxygen, only one-fifth to
one-fourth of lactic acid production during anaerobic contraction of the muscle is
subsequently oxidized to carbon dioxide and water. Thus, Meyerhof tied the release of
energy during this particular oxidation to the reconversion of the remaining four fifths
of the lactic acid back to glycogen.
These results had several important ramifications: they explained the course of heat
production measured by Hill; and they confirmed and extended a famous theory of Pasteur's
that less glycogen is consumed in muscle metabolism in the presence of oxygen than in its
absence. The depression of glycolysis by respiration was thereafter referred to as the
Pasteur-Meyerhof effect. This would be significant later on in working out the full details
of the glycolytic pathway. Finally and most importantly, the conversion of glycogen to
lactic acid and back again to glycogen was the first evidence of the cyclical character
of energy transformations in living cells. Meyerhof called it the lactic acid cycle.
Meyerhof and Hill's analysis of this cycle and its relation to respiration earned both
men the Nobel Prize in 1922.
Meyerhof and A.V. Hill, with whom he won the Nobel Prize, at the KWImF around 1931.
Standing in the background from left to right are Karl Lohmann, Alexander von Muralt,
Grigore Alexandru Benetato, Hermann Blaschko, Arthur Grollman,
H. Laser, his technicians
Fischer and Schulz and Eric Boyland.
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