Glucagon is a peptide hormone secreaed from the alpha cells of the islets of langerhans.
It results in raised blood glucose by:
- increasing gluconeogenesis in the liver
- increasing lipolysis
Glucagon is secreted in response to low blood glucose, raised catecholamines and raised plasma amino acids.
Glucagon secretion is inhibited by insulin, ketones in the blood, somatostatin and free fatty acids in the blood
A glucagonoma is a very rare tumour of the alpha cells of the islets of langerhans which secretes glucagon.
It results in:
- massively raised levels of glucagon
- diabetes mellitus
- hypoaminoacidaemia (as GNG is using up protein)
- necrolytic migratory erythema
Necrolytic migratory erythema is a red, blistering rash which is the presenting feature of a glucagonoma in 70% of cases.
Glucagonomas can be associated with MEN 1.
Treatment of a glucagonoma is ocreotide and surgery; prognosis is poor
For the really keen:
For the rest of us, its onwards to battle 21.3!