Pancreatic Pathology Online

The Apud Concept

Dr Sampurna Roy MD               July 2016


Tinctorial and histochemical properties shared by cells of  the pancreatic islets and endocrine cells of the gastrointestinal system suggest that they are phylogenitically related.


Visit: Anatomy of Normal Pancreas ; Normal Islets of Langerhans.

This idea is strengthened by the fact that with the exception of alpha and beta cells, which are restricted to the islets, all the other cells of the islets are also present to varying extents in the intestinal mucosa.

The uptake of amine precursors and their decarboxylation is a shared property that has led to a concept that links the islets and the gastrointestinal endocrine cells with other parts of the endocrine system and the autonomic nervous system.

A large and diffuse system assigned the acronym APUD (amino precursor uptake and decarboxylation), consists of different cell types.

The APUD concept postulates that the component cells of the system have a common derivation from the neural crest and neuroectoderm.

Later, this was expanded to include the neuroendocrine-programmed epiblast.

In support of this concept, many of the polypeptides synthesized by APUD cells are also synthesized in the brain, peripheral ganglia, and cells of the adrenal medulla.

The APUD concept has broadened our concept of the "endocrine system" and its complex biology, and our understanding of the histogenesis and function of tumours of the so-called gastroenteropancreatic system.


Further reading:

Evolution of the diffuse neuroendocrine system--clear cells and cloudy origins.

Disperse endocrine system and APUD concept.

The neuroendocrine system: organization and homeostatic role.

Endocrine markers of cellular immunity: defining the endocrine phenotype

The neuroendocrine phenotype, cellular plasticity, and the search for genetic switches: redefining the diffuse neuroendocrine system.

Immunocytochemical identification and localization of APUD cells in the gut of seven stomachless teleost fishes.

Tumors of the endocrine/neuroendocrine system: an overview.

Central and autonomic nervous system links to the APUD system (and their APUDomas).

Neuroendocrine system and its tumors.

Duct-acinar-islet cell tumor of the pancreas.

Non-functioning tumors of the endocrine pancreas. Concept, diagnosis, treatment.

The endocrine cells of the digestive tract. General concepts and historic perspective.

The neural crest: its relations with APUD and paraneuron concepts.

The APUD concept: where has it led us?

The APUD concept and its clinical significance. 2. Effect of gastrointestinal hormones, polypeptides and neurotransmitters on the physiological course and disease processes of the intestinal tract and the nervous system.




Dr Sampurna Roy  MD

Consultant  Histopathologist (Kolkata - India)






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