<Tr> <Td_colspan="4"> View / Edit Human </Td> <Td_colspan="0"> </Td> </Tr> <P> Glucagon is a peptide hormone, produced by alpha cells of the pancreas . It works to raise the concentration of glucose and fat in the bloodstream, and is considered to be the main catabolic hormone of the body . It is also used as a medication to treat a number of health conditions . Its effect is opposite to that of insulin, which lowers the extracellular glucose . </P> <P> The pancreas releases glucagon when the concentration of glucose in the bloodstream falls too low . Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream . High blood - glucose levels, on the other hand, stimulate the release of insulin . Insulin allows glucose to be taken up and used by insulin - dependent tissues . Thus, glucagon and insulin are part of a feedback system that keeps blood glucose levels stable . Glucagon increases energy expenditure and is elevated under conditions of stress . Glucagon belongs to the secretin family of hormones . </P> <P> Glucagon generally elevates the concentration of glucose in the blood by promoting gluconeogenesis and glycogenolysis . Glucagon also decreases fatty acid synthesis in adipose tissue and the liver, as well as promoting lipolysis in these tissues, which causes them to release fatty acids into circulation where they can be catabolised to generate energy in tissues such as skeletal muscle when required . </P>

High blood glucose levels stimulate the release of