APUD

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 early 60's. 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 - for high amine content.
 * Precursor Uptake - for high uptake of (amine) precursors.
 * Decarboxylase - for high content of the enzyme amino acid decarboxylase (for conversion of precursors to amines).