ABSTRACT
Gonadotropin releasing hormone (GnRH) is the primary hypothalamic regulator of reproductive function. With the help of a very small amount (250 µg) of GnRH derived from 160 000 porcine hypothalami, a group of scientists at Andrew Schally’s peptide laboratory in New Orleans was able to unravel the chemical structure of this compound in 1971.1,2 Roger Guillemin was able to characterize and also synthesize independently this neuroendocrine hormone. They both received the Nobel prize for their achievement. GnRH is a decapeptide that, like several other brain peptides, is synthesized as a part of a much larger precursor peptide, the GnRH associated peptide (GAP). This peptide is made up of a sequence of 56 amino acids. The availability of the synthetic hormone for dynamic endocrine testing and receptor studies created new insights into the physiological role of GnRH in the hypothalamic-pituitary-gonadal axis.3
