returned to Washington University in St. Louis in 1945, where he continued to do research in Cori's Laboratory. Sutherland accredits his decision to pursue a research career, as opposed to entering the medical profession, to his mentor Cori. Sutherland held various teaching titles during his time at the Washington University School of Medicine, including instructor in pharmacology (1945–46), instructor in biochemistry (1946–50), assistant professor in biochemistry (1950–52), and associate professor in biochemistry (1952–53). In 1953, Sutherland moved to Cleveland a position as a professor of pharmacology and chairman of the department of pharmacology at the school of medicine at Case Western Reserve University. There, he collaborated with Theodore W. Rall, also a professor of pharmacology, who was to become a lifelong research partner. Together, they conducted further research on the mechanism of hormone action at the molecular level. During his ten years at Case Western Reserve University, Sutherland made several ground-breaking discoveries that led to the identification of cyclic adenosine monophosphate, or cyclic AMP, and its role as a secondary messenger. In 1963, Sutherland became professor of anatomy at Vanderbilt University School of Medicine in Nashville. His position allowed him to devote more time to his research. He continued his work on cyclic AMP, receiving financial support from the Career Investigatorship awarded to him by the American Heart Association in 1967. He held his teaching title at Vanderbilt University until 1973. In 1973, after spending 10 years at Vanderbilt University, Sutherland moved to Miami, Florida, where he joined the faculty at the University of Miami's Leonard M. Miller School of Medicine as a distinguished professor of biochemistry. He continued to be involved in novel research about adenosine monophosphate and guanosine monophosphate, co-authoring four papers in 1973 alone. Discovery of cyclic AMP While working in Cori's laboratory, Sutherland, with the help of his co-workers, made several discoveries concerning the mechanism of glycogen metabolism that, years later, led him to his discovery of the biological activity of cyclic AMP. Cori's laboratory had previously established the basic mechanism of glycogen metabolism, for which they were awarded the Nobel Prize in Physiology or Medicine. Sutherland helped to identify the importance of liver phosphorylase (LP) in the process of glycogenolysis. Of the three basic enzymes involved in glycogenolysis, he found that LP was rate-limiting, meaning that the progression of glycogen metabolism is dependent on this enzyme. LP would become the subject of his research for