p75NTR and TrkC Neurotrophin Receptors Demonstrate a Different Immunoreactivity Profile in Comparison to TrkA and TrkB Receptors in Human Normal Pituitary Gland and Adenomas
| Autor: | Vassiliki Zolota, George Gatzounis, John Varakis, Christina Chondrogianni, Martha Assimakopoulou |
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| Rok vydání: | 2008 |
| Předmět: |
medicine.medical_specialty
Pituitary gland animal structures biology Endocrine and Autonomic Systems Endocrinology Diabetes and Metabolism Tropomyosin receptor kinase B Tropomyosin receptor kinase A Tropomyosin receptor kinase C Cellular and Molecular Neuroscience Endocrinology medicine.anatomical_structure nervous system Anterior pituitary Internal medicine medicine biology.protein Low-affinity nerve growth factor receptor Corticotropic cell Neurotrophin |
| Zdroj: | Neuroendocrinology. 88:127-134 |
| ISSN: | 1423-0194 0028-3835 |
| Popis: | Background/Aims: Recent knowledge indicates that neurotrophins play a significant role in neuroendocrine systems through their specific receptors TrkA, TrkB, TrkC and low-affinity p75NTR receptor. TrkA and TrkB receptors have been previously detected in numerous endocrine cells in human anterior pituitary and adenomas. In the present study, the localization of p75NTR and TrkC along with TrkA and TrkB receptors was investigated. Methods: Semi-serial paraffin-embedded sections of 5 human normal pituitaries and 30 adenomas were immunostained using specific antibodies. Results: Expression of p75NTR receptor was demonstrated in the intricate capillary and reticulin network in the anterior pituitary and in the pericapillary tissue and pituicytes in the posterior lobe. p75NTR immunoreactivity was absent from all adenomas. In normal anterior pituitary, a few scattered cells showed weak TrkC immunoreactivity in contrast to a high percentage of endocrine cells distributed throughout the pars distalis and pars intermedia which exhibited strong TrkA and/or intermediate TrkB immunoreactivity. Double immunohistochemistry demonstrated TrkA immunoreactivity in more than 80% of lactotropes and 70% of corticotropes and to a lesser extent in other cell types. Furthermore, in the majority of adenomas, independently of type, sex and age, a high percentage of TrkA- and/or TrkB-positive cells was detected. Interestingly, TrkC expression appeared to be increased in some adenomas compared to normal pituitary. Endothelial cells and perivascular connective tissue were always TrkB-immunostained. Conclusion: The above findings support a potential role of all neurotrophins, through their different receptors, in pituitary functions. |
| Databáze: | OpenAIRE |
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