Pancreatic polypeptide

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Pancreatic polypeptide (PP) is a polypeptide secreted by the pancreas. It consists of 36 amino acids and has a molecular weight of approximately 4200 daltons. Pancreatic polypeptide is produced by the PP cells (also known as F cells) of the islets of Langerhans in the pancreas.

Function

Pancreatic polypeptide plays a role in the regulation of both the endocrine and exocrine functions of the pancreas. It is involved in the regulation of gastric secretion, gallbladder contraction, and the modulation of hepatic glycogen levels. Additionally, it influences the secretion of other pancreatic hormones such as insulin and glucagon.

Regulation

The secretion of pancreatic polypeptide is stimulated by various factors, including:

• Food intake
• Hypoglycemia
• Exercise
• Vagal stimulation

Conversely, its secretion is inhibited by somatostatin and elevated levels of glucose.

Clinical Significance

Abnormal levels of pancreatic polypeptide can be associated with several medical conditions. Elevated levels may be observed in pancreatic endocrine tumors, such as insulinomas and gastrinomas. Conversely, reduced levels can be seen in conditions like type 1 diabetes mellitus and chronic pancreatitis.

Measurement

Pancreatic polypeptide levels can be measured in the blood using radioimmunoassay techniques. These measurements can be useful in the diagnosis and management of various pancreatic disorders.

See also

• Pancreas
• Islets of Langerhans
• Insulin
• Glucagon
• Somatostatin