APUD cell

APUD cells (DNES 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 (5-HTP) and dihydroxyphenylalanine (DOPA).
 * Decarboxylase – for high content of the enzyme amino acid decarboxylase (for conversion of precursors to amines).

Cells in APUD system

 * 1) Adenohypophysis
 * 2) Neurons of Hypothalamus


 * 1) Chief Cells of Parathyroid
 * 2) Adrenal Medullary Cells
 * 3) Glomus cells in Carotid Body
 * 4) Melanocytes of Skin
 * 5) Cells of Pineal Gland
 * 6) Renin producing cells in the kidney