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Pancreatic Polypeptide (PP)

المؤلف:  Norman, A. W., & Henry, H. L.

المصدر:  Hormones

الجزء والصفحة:  3rd edition , p135-136

2026-07-04

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 Pancreatic polypeptide (PP) is a 36-amino-acid pep tide that is known to stimulate the gastric secretion of HCl and pepsin (see Table 1). Most of the PP is expressed and then secreted by the G cells of the pancreas; see Figure 1A. PP circulates in the plasma as a dimer with a half-life of 6–7 minutes. The PP binds to its cognate receptor, the Y4 receptor, which is a G protein-coupled receptor. This is linked to inhibiting the production of the second messenger, cAMP. The Y4 receptor mRNA in humans is functionally active in the pancreas, colon, and small intestine. Pancreatic polypeptide can also act as a satiety factor. PP is known to be released after a protein meal. In a recent clinical study where PP was administered to human subjects, the main finding was that PP inhibited gastric emptying which then led to a reduction in food intake over a 24-hour interval.

Table1. Hormones Secreted by the Pancreas

Fig1. Schematic diagram of a human pancreatic islet with respect to the relative proportion of cells. The hormone secreting cells are, respectively, insulin (pink), glucagon (light green), and somatostatin (blue). Note that the A cells which secrete glucagon are basically all located on the perimeter of the islet, while the few cells that secrete somatostatin are located adjacent to the A cells. Also shown are the capillaries (dark red) which are evenly spread throughout the islet. The capillaries are connected to arterioles, which in turn are connected to venules  which deliver the released insulin, glucagon, or somatostatin into the general circulatory system.