The term glucagon was coined by Kimball and an immunoreactant in common with glucagon (gut Murlin (1923) to describe a hyperglycaemic sub-GLIs). The extensive similarities between the stance which they had partially purified from an sequences of glucagon, VIP, secretin, and GIP have extract of bovine pancreas. In 1953, Staub et al. been discussed elsewhere in these proceedings. The crystallised a pancreatic hyperglycaemic glyco-four peptides have very similar spectra of biological genolytic factor (HGF), for which they accepted the effects: secretin, glucagon, and VIP stimulate name glucagon in 1955 (Staub et al., 1955 (Sundby, 1976). the peptides to separate receptors on the cell surface. Avian glucagons differ from porcine glucagon; for The physiology of secretin, VIP, and GIP is described example turkey glucagon differs by having a serine elsewhere in these proceedings so the remainder of residue at position 28 instead of asparagine, and this section is restricted to the gut glucagon-like duck glucagon by also having a threonine at position immunoreactants (gut GLIs).