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Pancreatic polypeptide

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pancreatic polypeptide
PancreaticPolypeptide.jpg
IHC for Pancreatic Polypeptide in a mouse pancreas, 200x.
Identifiers
Symbol PPY
Entrez 5539
HUGO 9327
OMIM 167780
RefSeq NM_002722
UniProt P01298
Other data
Locus Chr. 17 p11.1-qter

Pancreatic polypeptide is a polypeptide secreted by PP cells in the endocrine pancreas predominantly in the head of the pancreas. It consists of 36 amino acids and has molecular weight about 4200 Da.[1]

The function of PP is to self regulate pancreatic secretion activities (endocrine and exocrine), it also has effects on hepatic glycogen levels and gastrointestinal secretions.

Its secretion in humans is increased after a protein meal, fasting, exercise, and acute hypoglycemia and is decreased by somatostatin and intravenous glucose.

Plasma PP has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa. In addition peripheral administration of PP has been shown to decrease food intake in rodents. [2] PP is secreted by PP pancreatic cells of Langherhans islets. It stimulates the gastric juice secretion, but inhibits the gastric secretion induced by pentagastrine. It is the antagonist of cholecystokinin and inhibits the pancreatic secretion which was stimulated by cholecystokinin. On fasting, PP seric concentration is 80 pg/ml; After the meal,it raises up from 8 to 10 times more; Glucose and fats, also induce PP's level increase, but on parentheral introduction of those substances, te level of hormones doesn't change. The administration of atropine, the vagothomy, blocks the PP's after meal secretion. The excitation of the vagus nerve, the administration of gastrin, secretin or cholecystokinin, induce PP secretion.

The augmentation of PP secretion was observed in hormonal-active pancreatic tumors (insulin, glucagon), in Werner-Morryson syndrome, and in gastrinomas.

References

  1. ^ Lonovics J, Devitt P, Watson LC, Rayford PL, Thompson JC (1981 Oct). "Pancreatic polypeptide". Arch Surg. 116 (10): 1256–64. PMID 7025798. http://www.ncbi.nlm.nih.gov/pubmed/7025798. 
  2. ^ http://jcem.endojournals.org/content/88/8/3989.abstract

External links

http://library.usmf.md/downloads/ebooks/Endocrinology_Anestiadi_en_2003/Lecture_11_p.(167-200).pdf


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