Differential Distribution of Serotonin and Tryptophan Hydroxylase in the Human Gastrointestinal Tract
| Autor: | Thomas Meyer, Ulrich Brinck |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Serotonin
medicine.medical_specialty Tryptophan Hydroxylase Biology digestive system 03 medical and health sciences 0302 clinical medicine Gastric glands Internal medicine medicine Humans 030304 developmental biology 0303 health sciences Lamina propria Gastroenterology Chromogranin A Epithelial Cells Tryptophan hydroxylase Immunohistochemistry Neurosecretory Systems Epithelium Small intestine 3. Good health medicine.anatomical_structure Endocrinology Enterochromaffin cell biology.protein Digestive System 030217 neurology & neurosurgery |
| Zdroj: | Digestion. 60:63-68 |
| ISSN: | 1421-9867 0012-2823 |
| DOI: | 10.1159/000007590 |
| Popis: | The distribution of tryptophan hydroxylase, the rate-limiting enzyme in the biosynthesis of serotonin, was investigated immunohistochemically in various organs of the gastrointestinal tract and compared with that of neuroendocrine markers. While immunoreactivity for serotonin and chromogranin A was restricted to enterochromaffin cells, positive staining for tryptophan hydroxylase was detected in normal enterocytes lining the epithelium of the small intestine. Tryptophan hydroxylase was localized in the supranuclear cytoplasm of absorptive cells, and was absent from the terminal web. The enterocytes of the exfoliation zone at the tips of the villi demonstrated a strong immunoreactivity similar to those at the slope of the villi. Mucus-containing Goblet cells, Paneth cells and stromal cells of the lamina propria remained unlabelled. The duodenal glands of Brunner revealed only sporadically a weak immunostaining for tryptophan hydroxylase. The monooxygenase was also detected in numerous secretory tubules of the pyloric mucosa, where the proportion of positive cells decreased progressively from the crypts towards the upper parts of the gastric glands. No significant immunoreactivity was demonstrated in colon, adrenal cortex, liver, pancreas, and mesenteric lymph nodes. The demonstration of tryptophan hydroxylase in normal enterocytes suggested that epithelial cells of the small intestine are able to synthesize 5-hydroxytryptophan. |
| Databáze: | OpenAIRE |
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