The 1977 Nobel Prize was awarded to Roger Guillemin, Andrew von Schally and Rosalyn Yalow for the discoveries concerning the brain production of peptide hormones, a type of hormone composed of a chain of amino acids - and for the development of radioimmunoassays of peptide hormones.
Although many important hormones such as insulin are peptide hormones, in the 1950s very little was known about them. This was largely because, unlike some other types of hormone, peptide hormones are present in extremely low concentrations in the blood, making them very hard to accurately detect and measure.
Rosalyn Yalow discovered that patients who had been given insulin developed antibodies to it, and that these antibodies preferentially bound to insulin that did not carry radioactive signalling molecules. She used these principles to develop the radioimmunological assay method (RIA), which quantified the amount of insulin present in a solution by measuring the proportion of radioactively-labelled insulin molecules bound to antibodies. RIA made further research into peptide hormones possible, and using a variety of animal models, Yalow went on to characterise insulin, ACTH and growth hormones, and the disorders that can result from their dysfunction. RIA has since been co-opted to detect and measure a wide variety of molecules in research and clinical settings.
In the 1950s, Roger Guillemin and Andrew von Schally were separately investigating the function of the brain’s hypothalamus to coordinate hormone release in disparate parts of the body. Experimenting in sheep and pigs, they isolated extracts from the hypothalamus that could bring about the release of different hormones from the pituitary gland. Ten years later, Guillemin and Schally were able to isolate, characterise and synthesise some of these ‘releasing factors’, finding them to be peptide hormones, and several others have been identified since.
The animal experiments conducted by Yalow, Guillemin and Schally yielded findings that were directly transferrable to humans, and provided researchers and clinicians with important insights into the endocrine system and its related diseases.