Glycogen Conversion between the Muscle and Liver is Cyclical
Contributed by: Sam B
Keywords
Animals, Carbohydrate metabolism, Cori cycle, Digestive system, Fundamental research, Historical figure, Lab, Medicine, Micronutrients, North America, Observational, Physiological/organismal ecology, Woman
Slides
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Resources
Cori, arl F, and Gerty T Cori. 1928. Glycogen formation in the liver from d- and l-lactic acid. link
Notes
Slide 1: Researcher’s Background
Dr. Cori (August 15, 1896 – October 26, 1957) was an Austro-Hungarian biochemist who won the 1947 Nobel Prize in science for elaborating the Cori Cycle which describes glycogen breakdown in muscle tissue. She was the third woman to win a Nobel Prize in Science, and she faced many barriers of entry into scientific research and struggled for many years to attain the salary, recognition and career status as her husband, a fellow researcher.
Biography in brief
Gerty Cori was born as a Jewish Czechoslovakian, who was admitted to medical school in Prague at 18 years old. She married Carl Cori after she graduated and immigrated to the United States a couple years after. Both Cori’s worked in research at Roswell University, with Gerty working as an associate in her husband’s lab. In 1928, both Cori’s became United States citizens, and completed work that unified the body’s regulation of energy storage and carbohydrate metabolism. This work was awarded the Nobel Prize in Medicine and Physiology in 1947. Dr. Cori continued to publish prolifically until 1957, when she succumbed to myelosclerosis. She achieved many notable and esteemed positions as a strong and established pioneering female scientist.
Is (or was) their research under-valued because of their identity?
Dr. Cori was only able to research due to her husband, as many universities did not accept female professors.
Are there other scientists/research examples that this example can replace or be added to?
Carl Cori
Slide 2: Research Overview
Take home message of study
By establishing the liver’s ability to convert lactic acid to liver glycogen, this study showed how the body converts energy into useable and stored forms in the process known as the Cori Cycle.
Study system
The Roswell Park Memorial Institute in Buffalo, New York (pictured left) was where the Gerty and Carl Cori (pictured right) performed experiments on carbohydrate metabolism. The 1928 study which elucidated the Cori Cycle won them the 1947 Nobel Prize in Medicine and Physiology.
Slide 3: Key Research Points
Main figure
This figure shows a summary of the process elucidated by this study. It was later termed the Cori cycle after the Gerty Cori and her husband who wrote the paper. Lactic acid and glucose in the bloodstream are used as energy, and muscle and liver glycogen are stored versions of these carbohydrates. This cycle begins with 1) liver glycogen conversion to blood glucose, 2) glucose conversion in into muscle glycogen, 3) muscle glycogen conversion to d-lactic acid, and finally 4) d-lactic acid conversion to liver glycogen. This Nobel-Prize winning study linked the opposing roles of the hormones epinephrine (which promotes step 3) and insulin (which promotes step 2), established the body’s mechanism to control energy use and storage, and helped situate diabetes as an imbalance in this cycle.
As described earlier, this cycle defines the cyclical nature of carbohydrate metabolism and storage in the body. The homeostatic balance of this process is regulated by epinephrine, which promotes the conversion of muscle glycogen to lactic acid, and insulin which promotes the conversion of the muscle glycogen to blood lactic acid. Glucose or lactic acid can be used by mitochondria to power cellular activities, and the storage or use of these molecules is an important to maintain bodily balance in cellular metabolism.
Societal Relevance
The research they performed is fundamental for a complete understanding of carbohydrate metabolism on an organism-wide scale. This is important for understanding diabetes’ dysfunction in the medical field. Additionally, the body’s method for maintaining blood sugar is a fundamental homeostatic mechanism used in medicine and physiology. Gerty Cori was one of the first prominent female scientists, and only the third woman to win a Nobel Prize as a result of this study.
