A Hormonal Happy Birthday
The word “hormone” made its scientific debut 108 years ago today. Photo by Alija/Getty Images
The word hormone has long been a familiar part of the English vernacular. It can refer to a wide variety of things from the life-saving medications, such as insulin and epinephrine, to the biological and psychological maelstrom of adolescence.
The study of internal secretions, or what we now call endocrinology (a word coined in 1904, by Maurice-Adolphe Limon, from the Greek roots for the study of within) was one of the major intellectual avenues of medical science during the late 19th and early 20th centuries. But the actual word, hormone, did not make its scientific debut until the great British physiologist Ernest H. Starling slipped it into his prestigious Croonian lecture, delivered to the Royal Society of Physicians in London, 108 years ago on June 20, 1905.
British physiologist Ernest Henry Starling (1866-1927). Photo by Time Life Pictures.
The hormone was probably first posed sometime earlier when the distinguished biochemist Joseph Needham invited Starling to dine with him at the high table of Caius College, Cambridge. The topic of the evening was Starling’s 1902 discovery of secretin, a protein that is considered by many to be the first isolated hormone.
Secretin is synthesized by the inner lining of the duodenum, a portion of the small intestines, and stimulates the pancreas to release a watery load of bicarbonate. This process of alkalization neutralizes the highly acidic stomach contents and facilitates the small intestine’s digestion of food. Upon hearing about this incredible chemical messenger, the classicist W.T. Vesey suggested calling it and kindred agents “hormones,” from the Greek root for “to set in motion, to excite, or arouse.”
Tall, impeccably dressed and quiet in tone, Professor Starling began his formal address to the British Empire’s best medical minds with a boldly accurate declaration:
From the remotest ages, the existence of a profession of medicine, the practice of its art and its acceptance as a necessary part of every community have been founded on a tacit assumption that the function of the body, whether of growth or activity of the organs, can be controlled by chemical means; and research by observation or accident or by experiment for such means has resulted in the huge array of drugs which from the pharmacopeias of various civilized countries and the common armamentarium of the medical profession throughout the world.
Starling went on to define hormones as “chemical messengers,” which are “carried from the organ where they are produced to the organ which they affect by means of the blood stream and the continually recurring physiological needs of the organism must determine their repeated production and circulation from the body.”
The first of four articles transcribing his momentous medical announcements about secretin and hormones appeared in print in the venerable Lancet on Aug. 5, 1905.
Ivan Pavlov watching an experiment with a dog. Photo by Sovfoto/UIG.
Interestingly, Starling’s assertion contradicted the opinion of the leading and most powerful physiologist of the day, Ivan Pavlov. Conducting an enormous laboratory staffed by dozens of eager students and assistants, Pavlov developed a theory called nervism, which ascribed the control of the body’s chemical messengers to the central nervous system. It was a view that many physiologists subscribed to and one that Pavlov believed was inviolable.
Starling and his brother-in-law, William M. Bayliss, repeatedly tried to reproduce Pavlov’s experimental findings that neural reflexes controlled the acid-base content of food as it passed from the stomach to the duodenum but they could not.
Although Starling and Bayless acknowledged that neural reflexes might play a role in the digestive process, their experiments led them to isolate and identify secretin. It was a discovery that spawned a revolution of biomedical thought and, as Starling boasted in his 1905 Croonian lecture, successful treatments for a long list of endocrine diseases.
Back in St. Petersburg, Pavlov ordered several of his acolytes to replicate Bayless and Starling’s experiments. Secretin’s importance — and Starling’s correctness — soon became obvious. Retreating to his study for an hour or more, the great Pavlov emerged to tell his students and colleagues, “Of course, they are right. It is clear that we did not take out an exclusive patent for the discovery of the truth.”
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