<P> Glucagon is generated from the cleavage of proglucagon by proprotein convertase 2 in pancreatic islet α cells . In intestinal L cells, proglucagon is cleaved to the alternate products glicentin, GLP - 1 (an incretin), IP - 2, and GLP - 2 (promotes intestinal growth). </P> <P> Abnormally elevated levels of glucagon may be caused by pancreatic tumors, such as glucagonoma, symptoms of which include necrolytic migratory erythema, reduced amino acids, and hyperglycemia . It may occur alone or in the context of multiple endocrine neoplasia type 1 . </P> <P> In the 1920s, Kimball and Murlin studied pancreatic extracts, and found an additional substance with hyperglycemic properties . They described glucagon in 1923 . The amino acid sequence of glucagon was described in the late 1950s . A more complete understanding of its role in physiology and disease was not established until the 1970s, when a specific radioimmunoassay was developed . </P> <P> Kimball and Murlin coined the term glucagon in 1923 when they initially named the substance the glucose agonist . </P>

What is glucagon and how does it work