APUD cell
image:Digestive [hormones.jpg|right|thumb|350px|Actions of the major digestive hormones secreted by APUD cells]
APUD cells constitute a group of apparently unrelated endocrine cells, which were named by the scientist A.G.E. Pearse, who developed the APUD concept in the 1960s based on calcitonin-secreting parafollicular C cells of dog thyroid. These cells share the common function of secreting a low molecular weight polypeptide hormone. There are several different types which secrete the hormones secretin, cholecystokinin and several others. The name is derived from an acronym, referring to the following:Amine Precursor Uptake – for high uptake of amine precursors including 5-hydroxytryptophan and dihydroxyphenylalanine.Decarboxylase – for high content of the enzyme amino acid decarboxylase.
Cells in APUD system
- Anterior pituitary
- Neurons of hypothalamus
- Chief cells of parathyroid
- Adrenal medullary cells
- Glomus cells in carotid body
- Melanocytes of skin
- Cells of pineal gland
- Renin producing cells in the kidney