Salk Distinguished Professor Emeritus Roger Guillemin, recipient of the 1977 Nobel Prize in Physiology or Medicine and neuroendocrinology pioneer, died on February 21, 2024, in Del Mar, California at the age of 100.
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Credit: Salk Institute
“We are incredibly saddened to learn of Roger’s passing,” says Salk President Gerald Joyce. “He leaves a remarkable legacy at Salk and around the world. His brilliance, commitment, and passion for discovery brought forth some of the last century’s most significant advances in our knowledge of the human brain. He was a cherished colleague and mentor to many. I personally mourn his loss and know I speak for the entire Salk community when I say our world is less bright without him in it.”
Guillemin joined Salk in 1970 to head the newly established Laboratories for Neuroendocrinology. He and his group discovered somatostatin, which regulates the activities of the pituitary gland and the pancreas. Somatostatin is used clinically to treat pituitary tumors. He was among the first people to isolate endorphins, brain molecules that act as natural opiates, and his work with cellular growth factors (FGFs) led to the recognition of multiple physiological functions and developmental mechanisms.
Guillemin played a key role in discovering the brain’s role in regulating hormones, substances that act as chemical messengers between different parts of the body and regulate bodily functions. While scientists had long believed that the brain ultimately controlled the function of hormone-producing endocrine glands, there had been scant evidence to prove exactly how it did so.
After meticulous study of materials harvested from 1.5 million sheep brains, Guillemin and his team made a breakthrough. They discovered releasing hormones, produced in small quantities in the hypothalamus of the brain. These are delivered to the adjacent pituitary gland, which in turn is triggered to release its own hormones that are dispersed through the body. Guillemin and Andrew Schally separately extracted a sufficient amount of one releasing hormone to determine its structure in 1969. They subsequently were able to produce it with chemical methods.
Their work would lead them to the 1977 Nobel Prize in Physiology or Medicine, shared also with Rosalyn Yalow for a separate but related discovery, for “discoveries concerning the peptide hormone production of the brain.”
This breakthrough resulted in the identification of a molecule called TRH (thyrotropin-releasing hormone), which ultimately controls all the functions of the thyroid gland. In the following years, he and his colleagues isolated other molecules from the hypothalamus that control all functions of the pituitary gland—for instance, GnRH (gonadotropin-releasing hormone), a hypothalamic hormone that causes the pituitary to release gonadotropins, which in turn trigger the release of hormones from the testicles or ovaries. This discovery led to advancements in the medical treatment of infertility and is also used to treat prostate cancer.
Guillemin was born in Dijon, the capital of France’s Burgundy region, on January 11, 1924. He entered medical school at the Université de Bourgogne in 1943, receiving his MD from the Faculté de Médecine in Lyon (then under the same academic administration as his university in Dijon) in 1949. Although he enjoyed learning about medicine and would practice it for several years before committing to research full-time, much of Guillemin’s youth and college experience was wrought with challenges—not the least of which was the German occupation of France. “Dark years of no fun these were,” he wrote.
Earning his Doctor in Medicine required the composition and defense of a dissertation, something that Guillemin looked forward to doing. “I had always been interested in endocrinology,” said Guillemin. “[An MD thesis] was usually pro forma. I decided, however, to write a dissertation… that I would enjoy, hopefully on some work I could perform in a laboratory.” A challenge to his desire to conduct research was a dearth of lab access. “There was no laboratory facility of any sort in Dijon, except for gross anatomy.”
In a fortuitous turn of events, Hans Selye was lecturing in Paris. Selye was a fellow pioneer of endocrinology, and an eager Guillemin made the journey to hear him speak. “A few months later,” Guillemin said, “I was in Selye’s newly created Institute of Experimental Medicine and Surgery at the Université de Montréal.” Guillemin would go on to earn his PhD in physiology, with a special focus on experimental endocrinology, from the university in 1953.
Shortly after completing his PhD, Guillemin became an assistant professor of physiology at the University of Baylor College of Medicine. Once there, he began to pursue the identity of the chemical mediators of hypothalamic origin, which were primary suspects for controlling pituitary function in the brain.
Guillemin was a mentor to many future leaders in endocrinology and medical research while at Baylor, including Catherine and Jean Rivier and Wylie Vale, who would all follow Guillemin to Salk in 1970 and themselves become professors there.
In addition to the 1977 Nobel Prize, Guillemin was the recipient of numerous accolades for his work. These included the Gairdner International Award, the Dickson Prize, the Passano Award, the Lasker Award, and the President’s National Medal of Science, presented to him by then-President Jimmy Carter. He was also an elected member of the National Academy of Sciences (1974) and the American Academy of Arts and Sciences (1976). Guillemin’s native France recognized his contributions to science and health by naming him a Commander in the Legion of Honour, the country’s highest order of merit. He served as the Salk Institutes’s interim president from October 2007 to February 2009.
For all of his accomplishments, Guillemin was always quick to point out the contributions of the many people who worked alongside him. “I have had the extraordinary privilege to work with wonderful collaborators, some so much more knowledgeable in their own field than I was (or still am), all full of enthusiasm and sharing the common ethics of science,” he wrote as he reflected on achieving the Nobel Prize.
When asked in a September 2017 interview with the La Jolla Light what his philosophy in life was, Guillemin responded, “Help people. I really wanted to be a physician… [and] I knew all my efforts would be to help people.”
Up until his last few years of life, Guillemin was an active member of the La Jolla, California community and was an avid collector of French and American paintings and sculptures, as well as Papuan and pre-Columbian pottery.
Guillemin is survived by his five daughters, one son, four grandchildren, and two great-grandchildren. He was pre-deceased by his wife, Lucienne, a talented musician, who died at the age of 100 in 2021, after the couple was married for 69 years. Guillemin died on her birthday.
