glucagon

glucagon

glucagon , hormone secreted by the α cells of the islets of Langerhans, specific groups of cells in the pancreas . It tends to counteract the action of insulin , i.e., it raises the concentration of glucose in the blood. Glucagon was first purified and crystallized in 1955; the amino acid sequence of this 29-amino acid polypeptide (see peptide ) was published in 1956-57. One of the most important actions of glucagon is the promotion of glycogenolysis, i.e., the degradation of glycogen to glucose, in the liver. Glucagon stimulates adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate to 3′5′-cyclic adenosine monophosphate (cyclic AMP).

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"glucagon." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"glucagon." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-glucagon.html

"glucagon." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-glucagon.html

Learn more about citation styles

glucagon

glucagon A polypeptide hormone secreted by the alpha-cells of the islets of Langerhans in the pancreas. By stimulating glycogenolysis (the breakdown of glycogen to glucose in the liver), it increases the level of glucose in the blood. Thus its function is antagonistic to insulin.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

MICHAEL ALLABY. "glucagon." A Dictionary of Zoology. 1999. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

MICHAEL ALLABY. "glucagon." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O8-glucagon.html

MICHAEL ALLABY. "glucagon." A Dictionary of Zoology. 1999. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-glucagon.html

Learn more about citation styles

glucagon

glucagon A hormone, secreted by the α (or A) cells of the islets of Langerhans in the pancreas, that increases the concentration of glucose in the blood by stimulating the metabolic breakdown of glycogen. It thus antagonizes the effects of insulin (see antagonism).

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"glucagon." A Dictionary of Biology. 2004. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"glucagon." A Dictionary of Biology. 2004. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O6-glucagon.html

"glucagon." A Dictionary of Biology. 2004. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-glucagon.html

Learn more about citation styles

glucagon

glucagon A hormone secreted by the α‐cells of the pancreas which causes an increase in blood sugar by increasing the breakdown of liver glycogen and stimulating the synthesis of glucose from amino acids.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

DAVID A. BENDER. "glucagon." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

DAVID A. BENDER. "glucagon." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-glucagon.html

DAVID A. BENDER. "glucagon." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-glucagon.html

Learn more about citation styles

glucagon

glu·ca·gon / ˈgloōkəˌgän/ • n. Biochem. a hormone formed in the pancreas that promotes the breakdown of glycogen to glucose in the liver.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"glucagon." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"glucagon." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O999-glucagon.html

"glucagon." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-glucagon.html

Learn more about citation styles

glucagon

glucagon (gloo-kă-gon) n. a hormone, produced by the pancreas, that causes an increase in the blood sugar level. Glucagon is administered by injection to counteract diabetic hypoglycaemia.

Show all research tools

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"glucagon." A Dictionary of Nursing. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>.

"glucagon." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O62-glucagon.html

"glucagon." A Dictionary of Nursing. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-glucagon.html

Learn more about citation styles

Free newspaper and magazine articles

Glucagon receptors: effect of exercise and fasting.(Clinical report)
Magazine article from: Applied Physiology, Nutrition, and Metabolism; 6/1/2005
Lilly Launches Glucagon for Injection (rDNA origin): Indicated for Treatment...
PR Newswire; 3/2/1999
GlucaGen[R] HypoKit (glucagon (rys)): an important consideration for all...
Magazine article from: Diabetes and Primary Care; 6/22/2002

Facts and information from other sites

glucagon images
glucagon. Wikimedia Commons (Public Domain)