Guillemin, Roger Charles Louis (1924- )

French-born US endocrinologist who was awarded a Nobel Prize for Physiology or Medicine in 1977 with his co-worker Andrew Schally for their discovery of hormones produced by the hypothalamus region of the brain. Guillemin isolated and identified various hormones, and also discovered endorphins. Guillemin and Schally shared the prize with US physicist Rosalyn Yalow, for her work on radioimmunoassay techniques by which minute quantities of hormone may be detected.

Guillemin found that the brain controls the pituitary gland by means of hormones produced by central neurons - the neurosecretory cells of the hypothalamus. He worked with Schally 1957-62, and later their investigations were parallel. Between 1968 and 1973 they isolated and synthesized three hypothalamic hormones which regulate the secretion of the anterior pituitary gland.

Guillemin was born in Dijon and educated there and at Lyon. He moved to the USA in 1953 and did most of his work at Baylor College of Medicine, Houston, Texas, becoming professor in 1963. In 1970 he joined the Salk Institute in La Jolla, California.