ABSTRACT
This chapter presents a brief outline of the nature and biosynthesis of glucagon. It aims to compare and contrast glucagon and insulin in terms of synthesis control and physiological actions. The chapter discusses the given symptoms of hypersecretion of glucagon. Glucagon is released between meals when plasma fatty acids and glucose levels fall. Secretion is inhibited when energy substrates, notably plasma glucose, ketone bodies and fatty acid levels rise in plasma. The autonomic system regulates glucagon release through both sympathetic and parasympathetic stimulation. Several gastrointestinal tract hormones stimulate glucagon release, for example, cholecystokinin and vasoactive intestinal peptide. Some physiological actions of glucagon are: promotes hepatic breakdown of glycogen to glucose, promotes hepatic glucose formation from amino acids, inhibits hepatic glycogenesis, and stimulates free fatty acid conversion to ketone bodies.
