Gerty Cori, a Life Dedicated to Chemical and Medical Research

Abstract

This article shows the life and work of Gerty Cori, a woman born in Czechoslovakia and who later became a naturalized American, who spent her whole life researching, together with her husband, in the laboratory to find the cause of some diseases, particularly those of a metabolic type, and to be able to find substances that alleviate their effects. The result of this joint work was the obtaining by both, together with the physiologist Bernardo Houssay, of the Nobel Prize in Medicine or Physiology in 1947. The objective of this article is to complete the scarce existing biographies about this woman with new data that highlight the most outstanding events of her life, quite a few of which are still largely ignored. A relatively complete information on the presence of female chemists in the awarded Nobel Prizes is also shown.

1. Introduction

This article follows a line of research already started a few years ago by the author, aimed at showing the biographies of women, both scientific and belonging to the fields of health, generally from the 19th and 20th centuries, who are quite unknown by society despite their great merits in the form of discoveries or transcendental milestones they had in their careers. The main objective of this research is to place these women as referents and models to society.

As far as Chemistry is concerned, the discipline to which this article refers, among the women dealt previously with in articles recently published, among them some in this same journal, are Gertrude Belle Elion, Nobel Prize winner in Physiology or Medicine in 1988 [1], Gabriella Morreale, the Italian–Spanish chemist who introduced the heel prick test in newborns [2], some pioneers of the Italian Chemistry, as Emma Fenaroli, Lidia Monti, María Piazza, María Ragno, Caterina Rossi or María Bakunin, for instance [3], several Asian women pioneers of Chemistry and Pharmacy, among them Janaki Ammal, the first Indian woman to obtain a doctorate [4] and pioneering Black African American female chemists and pharmacists, as Alice Ball, Patricia Bath, Mary Elliot Hill and Marie Maynard Daly, for instance [5].

Continuing then with this research and with the same objective of the mentioned papers, this article deals with the biography of Gerty Cori, Nobel Prize in Physiology or Medicine in 1947, shared with her husband, Carl Ferdinand Cori, and the physiologist Bernardo Alberto Houssay. She also has the honor of having uncovered the process of cellular energy storage and release, which allowed her and her husband, with whom she shared her research all her life, to understand how the human body works. This also made easier the study of biology, for using molecular chemistry for it.

The structure of the article is as follows. After this Introduction, Section 2 shows the materials and methods used in the research. As a way of contextualization, this section is followed by Section 3, in which some of the women chemists who won the Nobel Prize are remembered. Section 4 presents the most important biographical aspects of Gerty Cori’s life and scientific work, with special emphasis on those who contributed significantly to the development of human knowledge, and in particular to the advancement of Chemistry. A final section of Discussions ends the article.

2. Materials and Methods

For the elaboration of the article, information has been sought on Gerty Cori, with the objective of highlighting all the remarkable aspects of her life that are ignored in the scarce existing biographies about her.

3. Women Chemists and the Nobel Prize

At present, eight women have won the Nobel Prize in Chemistry. The first of them was Marie Curie (1867–1934), in 1911, along with Pierre Curie (her husband) and Henri Becquerel. This was her second Nobel Prize after the first one in Physics in 1903, Her prize in Chemistry was for her “discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element”. Her daughter Irene Joliot-Curie (1897–1956) was the second woman to be awarded this prize in 1935 for her discovery of artificial radioactivity. Later, Dorothy Mary Crowfoot Hodgkin (1910–1994) obtained the prize in 1964 for the development of protein crystallography. Many years later, in 2009, already in the 21st century, Israeli crystallographer Ada E Yonath (born in 1939), with Venkatraman Ramakrishnan and Thomas A. Steitz won the prize for the study of the structure and function of the ribosome. French microbiologist and biochemist Emmanuelle Charpentier (born in 1968) and American biochemist Jennifer A Doudna (born in 1964) won the 2020 prize in Chemistry “for the development of a method for genome editin”. They are the first women to share the Nobel Prize in that modality. In 2018, American Frances Hamilton Arnold (born in 1956) was awarded the Nobel Prize in Chemistry for pioneering the use of directed evolution to engineer enzymes. And finally, in 2022, American Carolyn R. Bertozzi (born 1966) was awarded a Nobel Prize for the development of click Chemistry and bio-orthogonal Chemistry”.

In addition to these eight women, there have been several other women either chemists or graduates in other scientific disciplines who have also obtained a Nobel Prize for their research related to Chemistry carried out throughout their lives, although these Nobel Prizes have been not in Chemistry, but in different modalities. Thus, the German-born American theoretical physicist Maria Goeppert Mayer (1906–1972) was a Nobel laureate in Physics for proposing the nuclear shell model of the atomic nucleus. That model of nuclear shells was a precedent for the creation of a new branch of Chemistry: Nuclear Chemistry. She was, after Marie Curie, the second woman to win a Nobel Prize in Physics. The American biochemist and pharmacologist Gertrude Belle Elion (1918–1999) shared the 1988 Nobel Prize in Physiology or Medicine with George H. Hitchings and Sir James Black (a complete biography on her can be consulted in [1]). And, as it will be seen after, another biochemist, Gerty Cori, who is the person referred to in this article, also obtained the Nobel Prize in that modality of Physiology or Medicine, in 1947.

Moreover, we do not want to leave these brief notes about the women chemists who have obtained the Nobel Prize without indicating that there have also been several of them who were not finally awarded that prize despite amply deserving it, on some occasions just because of “being a woman”. Among them, we can mention the Austrian Marietta Blau (1894–1970), who stood out in the physicochemical sciences, being a pioneer in the application of the photographic method to record subatomic particles, which let her have two Nobel Prize in Physics nominations. In 1950, Thérèse Tréfouël (1892–1978) was nominated together with her husband Jacques for the Nobel Prize in Chemistry for the discovery of a new class of antibacterial agents, the sulfonamides. Martha Chase (1927–2003) carried out in 1952, along with Alfred Hershey, experiments with the T2 phage to prove that DNA was the basis of genetic material. Only Alfred Hershey won the Nobel Prize in Physiology or Medicine in 1969, despite the fact that the work was joint. And in 1934, Ida Tacke-Noddack (1896–1978,) proposed the process of nuclear fission, which allowed her, five years later, to be nominated three times for the Nobel Prize in Chemistry, what never succeeded (see [6,7,8] for further information on these subjects).

As previously cited, Gerty Cori is also part of one of the five marriages that have been awarded a Nobel Prize throughout history. In chronological order of receiving that award, these five marriages have been as follows:

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In 1903, French–Polish Marie Curie and her French husband Pierre Curie received the Nobel Prize in Physics for the discovery of natural radioactivity.

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In 1935, French Irène Joliot-Curie, Marie Curie’s daughter, and Frédéric Joliot were awarded the Nobel Prize in Chemistry for the synthesis of new radioactive elements.

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In 1947, Americans Gerty and Carl Cori received the Nobel Prize in Medicine for their research on enzymes in animal tissues.

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The Swedes Alva and Gunnar Myrdal form the fourth couple to have been awarded the Nobel Prize, although unlike the other four couples, they did not receive it at the same time or in the same category. Gunnar Myrdal received in 1974 the Nobel Memorial Prize in Economic Sciences, joint with Friedrich Hayek for their pioneering work in the theory of money and economic fluctuations and for their penetrating analysis of the interdependence of economics. For his part, his wife, Alva Myrdal, along with Alfonso García Robles (Mexican diplomat and politician) received the Nobel Peace Prize in 1982.

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In 2014, Norwegians May-Britt and Edvard Moser won the Nobel Prize in Medicine for discovering fundamental structures of the human sense of orientation.

All of the above shows that many women chemists from the late 19th century or early 20th century have had a strong relationship with the Nobel Prizes, both in the Chemistry modality and in different ones, thus opening the door for other women chemists from currently follow that path. Additionally, one of them was Gerty Cori who, as it has been indicated, has the honor of having been the first woman to be awarded the Nobel Prize in Physiology or Medicine. She is the female chemist whose biography is featured in this article.

4. Biography of Gerty Cori (nee Radnitz)

In this section we show the biography of Gerty Cori, who reached great scientific achievements and discoveries in Chemistry, Pharmacy and Medicine, which made her worthy of being awarded, together with her husband, with whom she worked throughout her life, and another Argentinian colleague, the Nobel Prize in Physiology or Medicine, in 1947.

Gerty Theresa Radnitz was born in Prague on 15 August 1896, into a Jewish family. Her father, Otto Radnitz, was a chemist who worked at the University, which he left to become manager of a sugar refinery when he invented a successful refining method. Her mother was an educated woman, who counted among her friends very relevant people of the time, such as the writer Franz Kafka (1883–1924), author of the well-known novels “The Trial”, The Castle” and “The disappeared”, all of them originally written in German, despite being born in the Czechoslovak region of Bohemia [9].

Because the time in which she was born made it very difficult for women to study in the country and later practice their professions, she carried out her first studies in her own home, with the help of private teachers, and later entered a school for girls.

She had decided to study Medicine, to follow the example of a maternal uncle who was a professor of Pediatrics at the University of Prague. For this reason, after overcoming several difficulties to be admitted, she managed to pass the admission exam for the School of Medicine of the German Carl Ferdinand University, in Prague, in 1914, at the age of 16 [10]. The admission of students to that university was very hard, since that institution, founded in 1348 by the Holy Roman emperor Charles IV, from whom it takes its name, was the first university in central Europe and had great prestige. That explains that Gerty Cori had to spend a year dealing with what she later called “the hardest examination I was ever called upon to take” [11].

At that school, where she obtained her doctorate in Medicine in 1920, she met her future husband, Carl Ferdinand Cori (Praha, 1896–1984). Indeed, she and Carl met in anatomy class and became inseparable, studying, walking, enjoying, hiking, skiing, and researching together. They married right after she received her degree, aged 24 (Figure 1).

By this time, having already adopted the name Gerty Cori, she converted to Catholicism, which was Carl’s religion. After the wedding they moved to Vienna, where Gerty spent the next two years working at the Children’s Carolinen Hospital, while Carl worked in a laboratory [10]. Since that wedding, Carl Ferdinand Cori would become not only Gerty’s husband, but also her lifelong research partner.

During her stay at the hospital, she began work on an intense task. Gerty worked in the Pediatric unit and took the opportunity to carry out research on temperature regulation, comparing temperatures before and after treatment for thyroid pathology, which allowed her to publish articles on blood disorders [9].

However, the conditions of life in practically all of Europe became very difficult after the First World War, and she even suffered xerophthalmia (The word “xerophthalmia” comes from the ancient Greek: “xērós” (which means “dry”) and “ophthalmos” (“eye”). It names a medical condition that causes the eye to not produce tears, resulting in pathological dryness of the conjunctiva and cornea. The most common cause of its occurrence is a severe vitamin A deficiency. The conjunctiva becomes dry, thick, and wrinkled. Its first symptom is poor vision at night, and if not treated early, it can lead to dry eye syndrome, ulceration of the cornea, and ultimately blindness as a result of corneal and retinal damage.) due to a great deficiency of vitamin A produced by severe malnutrition caused by lack of food. All this, to which was also added the appearance of a growing anti-Semitism, made the couple leave Europe, deciding to emigrate to the United States in 1922.

That decision to leave Europe that the couple took is not strange, since it must have been very thoughtful. Note that, apart from the serious economic consequences that this war produced, the social consequences that it brought with it were very important. To begin with, the great mortality that originated and the decrease in the birth rate and the workforce caused the impoverishment of the population, which provoked strong social tensions. In addition, with regard to women, the few advances of a social nature that they had achieved during the conflict experienced a strong setback. When men returned to the world of work, they forced women hopelessly back into the domestic sphere. There was no work for everyone, and women were once again sacrificed, remaining unemployed.

Moreover, due to the difficulty she had in finding jobs in United States that would allow her to work and research, since the ones she was offered were very poorly paid, it was Carl who first emigrated and then Gerty six months later, to dedicate herself to medical research at the State Institute for the Study of Malignant Diseases (now Roswell Park Cancer Institute) in Buffalo, New York.

Although the Institute authorities continually discouraged them from continuing to work together, they both ignored these recommendations and continued to work together, specializing in research on carbohydrate metabolism. They were particularly interested in understanding how glucose is metabolized in the human body and the hormones that regulate this process [10]. The result of their joint collaboration were the fifty articles that they published while working at the Institute, appearing in them as the first author who had carried out most of the research in that article. For her part, Gerty Cori (Figure 2) also published eleven articles as the sole author.

In 1928, the couple obtained American nationality [14], and the following year they proposed the theoretical cycle that would later award them the Nobel Prize, the Cori cycle, a cycle that describes the way in which the human body uses some chemical reactions in muscle tissue, to transform carbohydrates such as glycogen into lactic acid, while at the same time the synthesis of others occurs (see Section 5).

The couple left their job at the current Roswell Institute after publishing their work on carbohydrate metabolism, although she found many difficulties, most of them inherent to the role assigned to women in American culture, to find another job. Some universities offered Carl a job, but refused to hire his wife (in fact, in one of the interviews, Gerty was told that it was considered “un-American” for a married couple to work together”) [9].

After several previous attempts, in 1931 the couple moved to St. Louis, Missouri, where Carl was offered a position as a researcher at the Washington University School of Medicine. Despite her background, however, Gerty was only offered a position as a research associate, at a salary that was one-tenth of what Carl earned [15]. In addition, she was told that that she could harm the career of her husband [14]. However, she accepted those conditions and many years later, in 1943, she managed to be appointed research associate professor in Biochemistry and Pharmacology and also, months before she won the Nobel Prize, she was promoted to full professor, a position she held until her death in 1957 [15].

Both continued to work collaboratively at the University of Washington. In their analyses using ground frog muscle, they discovered an intermediate compound that allowed the breakdown of glycogen, called glucose-1-phosphate (now known as Cori’s ester). They established the structure of this compound, identified the enzyme that catalyzes its chemical formation, glycogen phosphorylase, and demonstrated that Cori’s ester is the initial step in the conversion of the carbohydrate glycogen to glucose, of which large amounts exist in the liver [16,17].

It is important to note that, apart from the work of Carl Ferdinand and Gerty Cory, very important discoveries for science were made in the laboratory of the University of Washington, which made it a reference in experimental biochemistry in the 40s and 50. Very important researchers worked in that laboratory, some of whom became Nobel Prize winners, such as Arthur Kornberg, Severo Ochoa, Luis Leloir, Earl Sutherland, Christian de Duve y Edwin G. Krebs (Note: Arthur Kornberg (1918–2007), American biochemist, Head of the Departments of Microbiology at Washington University in St. Louis and Biochemistry at Stanford University, who along with Severo Ochoa, was awarded the 1959 Nobel Prize in Physiology or Medicine. Severo Ochoa de Albornoz (1905–1993), Spanish doctor and scientist, naturalized American in 1956, internationally renowned. In 1959 he was awarded the Nobel Prize in Physiology or Medicine, together with Arthur Kornberg. In 1974 he moved as a distinguished researcher to the Roche Institute for Molecular Biology in New Jersey. He retired from New York University in 1975. Although born in France, Luis Federico Leloir (1906–1987), physician and biochemist, was educated and lived his entire life in Argentina. In 1970 received the Nobel Prize in Chemistry for his discovery of the metabolic pathways by which carbohydrates are synthesized and converted into energy in the body. The American pharmacologist and biochemist Earl Wilbur Sutherland Jr. (1915–1974) obtained a Nobel Prize in Physiology or Medicine in 1971 for “his discoveries concerning the mechanisms of the action of hormones”, especially epinephrine, via second messengers, called namely cyclic adenosine monophosphate. The British Christian René Marie Joseph de Duve (1917–2013), professor of biochemistry at the University of Louvain, and at the Rockefeller Institute in New York, won the Nobel Prize in Physiology or Medicine in 1974, shared with Albert Claude and George Emil Palade, for “having described the structure and functions of the different organelles inside cells”. In 2010 he abandoned Catholicism and converted to Agnosticism. He chose euthanasia (assisted sui-cide) to die, after seeing how his health deteriorated significantly in recent months. The American physician and biochemist Eddwin Gerhard Krebs (1918–2009) was appointed Professor of Biochemistry at the University of Washington, where his joint work with Edmond H. Fischer on various aspects of cell activity earned them both the 1992 Nobel Prize in Physiology or Medicine. The main result of both was to discover the existence of a reaction that regulates the activity of certain enzymes involved in phosphorylation (the so-called “Krebs Cycle”).).

Figure 3 shows a group of women at the Washington School of Medicine, June 1939. Gerty Cori is standing, fifth from the right. She was working as a research associate in pharmacology at the time.

As has already been indicated several times, Gerty Cori and her husband Carl Ferdinad Cori were two inseparable people, both in their personal and professional lives, since in all the places where they were working and researching, they did so together. Figure 4 shows an image of them working in the laboratory.

Gerty and Carl carried out most of their work collaboratively, including that which ultimately led them to earn their Nobel Prize in Physiology or Medicine in 1947, for “their discovery of the process of the catalytic conversion of glycogen”. Concretely, their work consisted of continuing their research on glycogen and glucose and describing glycogenolysis, identifying and synthesizing the important enzyme glycogen phosphorylase (see Figure 5).

They both shared the prize with the physiologist Bernardo Alberto Houssay (Buenos Aires, 1887–1971), an Argentine physiologist, professor and pharmacist who was the first Latin American to be awarded a prize in Sciences (since Carlos Saavedra Lamas, also an Argentine, had won the Nobel Prize of Peace in 1936). Bernardo Houssay was awarded for “his discovery of the role played by the hormone of the anterior pituitary lobe in sugar metabolism” (The Argentinian professor, doctor and pharmacist, born and died in Buenos Aires, Bernardo Alberto Houssay (1887–971) was awarded the Nobel Prize in Medicine in 1947, together with the marriage formed by Carl Ferdinand and Gerty Cori, for its discoveries on the role pituitary hormones play in regulating the amount of sugar in the blood. He was the first Latin American laureate in Science (his compatriot Carlos Saavedra Lamas had also won a Nobel Prize in 1936, in the Peace modality). His work made physiology the medical discipline that achieved the greatest vigor and development in Argentina at that time.).

Subsequently, they continued with their investigations to clarify the mechanisms of carbohydrate metabolism, achieving advances in the understanding of the reversible conversion of sugar and starch. Their discoveries were crucial for the development of new treatments for diabetes [9].

Just before winning the Nobel Prize and while she and her husband were on a climbing trip, Gerty was discovered to be ill with myelosclerosis, a deadly disease of the bone marrow. Because of this, she constantly needed to receive blood transfusions and later underwent a splenectomy. Despite her health problems, she remained active at work and in research and became involved in the study of glycogen diseases, also called glycogen storage diseases, which were the subject of the last article she published [17]. For ten years she battled the disease while continuing her scientific work, which only slowed down during the last months of her life. Gerty Cori (Figure 6) died at her home on October 26, 1957, at the age of 61, survived by her husband (who passed away 27 years later) and their only child, Thomas (Tom) Cori.

During the funeral service, the already mentioned Spanish doctor and scientist, who became a naturalized American in 1956, and who was also awarded the Nobel Prize in Physiology or Medicine in 1959, Severo Ochoa de Albornoz (1905–1993), said the following about her [17], “Gerty, for all of us, was a human being of great spiritual depth. Modest, kind, generous and affectionate to a superlative degree and a lover of nature and art.”

Two months later, in a posthumous tribute that the University of Washington gave her, Bernardo Houssay, the Argentine physiologist who shared the Nobel Prize with the Cori, expressed in a speech [18],

Gerty Cori’s life was a noble example of dedication to an ideal, the advancement of science and for the benefit of humanity. Gerty Cori’s charming personality, so rich in human qualities, earned the friendship and admiration of all who had the privilege of knowing her. [...] Her name is forever etched in the annals of science and her memory will be cherished by her many friends as long as we are alive.

After the death of Gerty Cori, Carl Fedinand Cori would marry Anne Fitzgerald-Jones, in 1960, with whom, as with Gerty, he had common hobbies, such as archaeology, art, and literature. Six years later, he retired from Washington University and was appointed visiting professor of Biological Chemistry at Harvard Medical School. At the same time, he maintained a laboratory at Massachusetts General Hospital. He continued his research until he became very ill in the 1980s [9].

Gerty Cori and her husband (Figure 7) received numerous accolades, awards, and honors for their discoveries, both in life and in death.

Among all those distinctions, the following can be highlighted:

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The Cori crater on the Moon was named in her honor.

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In 1948, Gerty was awarded the Garvan-Olin Medal, a decoration in recognition of distinguished work in chemistry given to American women chemists.

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She was appointed by President Harry S. Truman to the board of National Science. Foundation, a position she held until her death. She was also elected to the United States National Academy of Sciences, the fourth woman to receive that honor [15].

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She also shared a star with her husband Carl on the St. Louis Walk of Fame on 15 May 1994 (Star Location: 6605 Delmar) [19].

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In 2004, Gerty and Carl were designated a National Historical Chemical Landmark by the American Chemical Society, in recognition of their work in elucidating carbohydrate metabolism [9].

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The Cori (glucose-1-phosphate) ester formula was printed on a United States Postal Service stamp in April 2008 (Figure 8) [20]. Although the Associated Press reported on 15 January 2008 that the 41 cent stamp had a printing error in the formula, the stamp was distributed despite that error. Its description reads, “Biochemist Gerty Cori (1896–1957), in collaboration with her husband Carl, made important discoveries, including a new derivative of glucose, which elucidated the steps of carbohydrate metabolism and contributed to the understanding and treatment of diabetes and other metabolic diseases”.

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Carl and Gerty Cori appeared on the “American Scientists” series along with other scientists, including chemist Linus Pauling, astronomer Edwin Hubble, and physicist John Bardeen (Linus Carl Pauling (1901–1994), American chemical engineer, biochemist, and activist, has the honor of being one of the first quantum chemists to be twice awarded the Nobel Prize, the first for Chemistry, in 1954, for his work in which he described chemical bonds and the second with that of La Paz, in 1962, for his campaign against terrestrial nuclear tests. Both Nobel Prizes were awarded to him individually and he was also awarded the Lenin Peace Prize in 1969 for his activism and defense of Human Rights. Edwin Powell Hubble (1889–1953) is one of the most important American astronomers of the 20th century. He demonstrated in 1929 the expansion of the universe by measuring the redshift of distant galaxies. In 1917, he obtained a doctorate in physics from the Yerkes Observatory of the University of Chicago. After the end of the First World War, in 1919, he began working at the new Mount Wilson observatory, where he managed the most powerful telescope in the world at that time. Today there is a satellite named “Hubble” in his honor. The American electrical engineer from the University of Wisconsin-Madison, in 1923, and later physicist and mathematician from Princeton University, in 1936, John Bardeen (1908–1991), is one of only five people who have managed to be awarded with two Nobel Prizes, in his case both in Physics, in 1956 and 1972. The other four people are Marie Curie, Linus Pauling, Frederick Sanger and Barry Sharpless. In 1943 he was invited to participate in the Manhattan Project, but he declined the invitation).

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The US Department of Energy named the NERSC-8 supercomputer in her honor, a Cray XC40 installed in 2016 at the Lawrence Berkeley National Laboratory, which became the fifth most powerful supercomputer in the world [21].

Some of Gerty Cori’s views expressed at different times in her life were as follows [11]: “I believe the benefits of two civilizations—a European education followed by the freedom and opportunities of this country—have been essential to whatever contributions I have been able to make to science.” “The unforgotten moments of my life are those rare ones which come after years of plodding work, when the veil over nature’s secret seems suddenly to lift, and when what was dark and chaotic appears in a clear and beautiful light and pattern.”

Her son Tom Cori, remembering his mother, once claimed about her that [9]: “My grandfather, that is, my mother’s father, toward the end of his life became diabetic and he said to his daughter, who was a doctor, “Find me a cure”.”

5. Discussion

This article is dedicated to reveal the life of Gerty Cori, a Czechoslovakian, later naturalized American woman chemist not well known by society, although her scientific work had an enormous importance and represented a great advance, not only for Chemistry, but also for the treatment of diseases, since that work allowed us to understand metabolic processes, find new enzymes, locate the enzymatic functions, and treat the enzyme deficiency presented in several diseases. For all this, she deserves the greatest recognition from society, although it is fair to recognize that part of that merit is also due to her husband Carl Ferdinand, with whom she always maintained a truly collaborative relationship.

Indeed, it is possible that perhaps today it is difficult to realize the great advance that the scientific contributions of Gerty Cori and her husband represented at the time. In the 1920s it was unknown how the body can provide energy to the tissues not only with food, but even during fasting or intense exercise. The Cori defined the importance of glycogen, the reserve polysaccharide, similar in structure to plant starch, which allows glucose to be stored in animal cells. They established the connection between the metabolism of glucose in the muscle and that of glycogen in the liver. This interorgan glucose–lactate cycle, known today as the “Cori cycle,” describes how lactate produced by glycolysis in working muscle is transported to the liver, where glucose is synthesized and returned to the muscle or stored as glucose until it is needed (see Figure 9).

After these physiological studies, the Coris went on to carry out the biochemical study of glycogen metabolism, describing intermediate substances such as glucose-1-phosphate (also called “Cori ester”) and enzymes such as glycogen phosphorylase and phosphoglucomutase. This allowed them to synthesize a large biological molecule (glycogen) for the first time in vitro. As a result of this enormous work, it has already been mentioned that the Cori published fifty joint research articles, many of them in “The Journal of Biological Chemistry”, and Gerty Cori also published eleven articles as the sole author. All of the titles can be consulted in [22].

In addition, Gerty Cori’s extensive training in medicine, physiology and pathology enabled her to integrate and correlate her biochemical discoveries with pathology, characterizing four different types of diseases caused by deficiencies in glycogen metabolism enzymes. These pioneering studies would inspire biomedical research that led to the identification of numerous genetic diseases of metabolism (further information on the clinical and medical work of the Cori couple can be obtained in the splendid work by Giralt, in 2010 [23], from which part of the previous paragraphs have been extracted.