The Prostatic Neuroendocrine Cell
Prostatic neuroendocrine cells are intraglandular
and intraductal hybrid epithelial/ neural/ endocrine cells
which express/ secrete serotonin and numerous peptides/ neuropeptides.
Prostatic neuroendocrine cells are generally
widely scattered throughout the prostate with only an occasional
cell per gland/ duct, but are most consistently found in the
periurethral ducts and verumontanum. A small percent of human
prostates contain numerous neuroendocrine cells.
Prostatic neuroendocrine cells are of
the open and closed cell types. The open cell type has an apical
cytoplasmic process which extends to the lumen and has long
specialized surface microvilli. These cells resemble sensory
cells such as olfactory and taste bud cells. Both types of
neuroendocrine cells also have long branching dendrite-like
processes which extend between nearby epithelial cells. In
addition to physically communicating with non-neuroendocrine
epithelial cells, neuroendocrine cells also appear to communicate
with each other via these dendrite-like processes. Both afferent
and efferent nerves innervate prostatic neuroendocrine cells.
Ultrastructural studies have shown a wide range of neurosecretory
granule morphology which correlates with the large number of
known secretory products:
Prostate Neuroendocrine Cell Products
- Chromogranins
- Serotonin
- Gastrin releasing peptide (bombesin)
- Calcitonin gene family
- Somatostatin
- Parathyroid hormone-related protein
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- Neuropeptide Y
- Vascular endothelial growth factor
- Cholecystokinin
- Proadrenomedullin N-terminal peptide
- TSH-like peptide
- Histamine
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Receptors for neuroendocrine products have been found in normal
and/or neoplastic prostate.
Prostate Neuroendocrine Receptors
(normal prostate
and/or cancer)
- Gastrin releasing peptide (GRPR)
- Serotonin (5HT1a)
- Somatostatin (SST 1-5)
- Calcitonin (hCTR-2)
- Cholecystokinin (CCK-a)
- Neuropeptide Y (NPY1 and NPY2)
Evidence suggests that neuroendocrine cells regulate the growth,
differentiation and secretory activity of the prostatic epithelium
through paracrine, endocrine and neurocrine mechanisms. The
open type may "taste" the glandular lumenal contents
and adjust the epithelial secretions as needed via paracrine
signals to adjacent epithelial cells, reflex neural loops or
endocrine signalling to distant sites such as the hypothalamic/
pituitary axis or the testis.
This hypothesized role for the prostatic neuroendocrine cell
is based on the known actions of the prostatic peptides/ neuropeptides
in other organ systems, the morphology of the cells, experimental
studies, and analogy with the much more extensively studied
neuroendocrine cells of the gastrointestinal, pancreatic, thyroid
and pulmonary organ systems. These prostatic neuroendocrine
cells are nearly identical to those in the gastrointestinal
tract which play a major role in digestion, motility, satiety,
food seeking behavior, etc. They are also closely related to
lung neuroendocrine cells which regulate lung growth and differentiation
via bombesin-like peptides.
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