APUD cells, apudomas and the neural crest.

The most characteristic feature of the APUD cell series is the ability to take up and decarboxylate amine precursors. Other features, regarded as characteristic by Pearse, are the secretion of polypeptide hormones and their origin from the neural crest. An increasing number of APUD cells is being shown to elaborate polypeptide hormones. It is acknowledged that some members are derived from the neural crest, but there is a good reason to believe that others are not, and no good reason to believe that yet others are so derived. It is therefore suggested that the common factor sought in the genesis of the APUD cell, and perhaps other tumours, may be the biochemical, rather than the embryological, relationship of the progenitor cell types.