Secretion of Corticotrophin and Somatotrophin by the Senescent Adenohypophysis in Man

A discussion of the physiological qualities of corticotrophin and somatotrophin is of relevance with a view to the later approach to the problems. It is not the intention to give a detailed account of these matters; this will lead far beyond the limits of the subject at issue. The chemical structure of corticotrophin, the regulation of secretion and its biological action are considered on the basis of an overall review of some large-scale studies by Evans et al. (1966a), Fortier (1966), Mess & Martini (1968), MacDonald et al. (1969), Harris & George (1969), Sayers & Travis (1970), and Thorn (1972). The hormone is a peptide composed of a single, unbranched chain of 39 amino acids. The sequence of the first 24 amino acids and the last six is identical in the sheep, the ox, pig and man. The biological action resides in the 24 N-terminal amino acids