Discovery of Thyrotropin-Releasing Hormone

The discovery of thyrotropin-releasing hormone, or TRH, was the first determination of the chemical structure of a hormone that the hypothalamus uses to control the pituitary gland. TRH is a tripeptide made of pyroglutamyl-histidyl-proline amide, produced by neurons in the hypothalamus, and it stimulates the pituitary to release thyroid-stimulating hormone and prolactin. Its structure was first determined, and the hormone synthesized, by Roger Guillemin and Andrew V. Schally in 1969, working in separate laboratories. Both men insisted that their own laboratory had the sequence first: Schally had suggested the possibility in 1966 but abandoned it after Guillemin argued it was not a peptide, and the two returned to the work in 1969 when the National Institutes of Health threatened to cut off funding. Press accounts stressed their fierce competition and the very large number of sheep and pig brains they processed. The two shared the 1977 Nobel Prize in Physiology or Medicine for discoveries concerning the peptide hormone production of the brain. TRH has since been used in the TRH test for diagnosing the cause of hypothyroidism.