Somatostatin-14 alters the thymus size and relation among the thymocyte subpopulations in peripubertal rats
Autor: | D.J. Kosec, Ana K. Rakin, Mileva V. Mićić, Walter B. Severs, Lj.A. Dimitrijević, Danica M. Petrović-Đergović, I.P. Živković, Vesna Starcevic |
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Rok vydání: | 2004 |
Předmět: |
Male
medicine.medical_specialty Receptors Antigen T-Cell alpha-beta Double negative Neuropeptide Thymus Gland thymocyte subpopulations Biology Peptide hormone CD8-Positive T-Lymphocytes 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine Endocrinology T-Lymphocyte Subsets thymus Cortex (anatomy) Internal medicine medicine Animals rat Lymphocyte Count Sexual Maturation 030304 developmental biology Cell Size Injections Intraventricular 0303 health sciences Endocrine and Autonomic Systems General Medicine Organ Size Flow Cytometry Prolactin CD4 Lymphocyte Count Rats somatostatin-14 Thymocyte medicine.anatomical_structure Somatostatin Neurology CD8 TCR morphometry 030215 immunology |
Zdroj: | Neuropeptides |
Popis: | It is well known that somatostatin exerts a wide range of effects in the body, and acts as an antocrine or paracrine factor in the thymus. However, it has not been investigated yet whether somatostatin alters the thymus size and relation among the thymocyte subpopulations in the peripubertal rats. For this purpose, the peripubertal AO male rats were cannulated intracerebroventriculary and treated with repeated, low doses of somatostatin-14 (experimental group) or saline (control group). Twenty-four hours after the last treatment, we removed and prepared the thymuses for determination of thymocyte subpopulations by flow cytometry. After five days, animals were sacrificed and their thymuses taken for morphometrical analysis by stereological methods. We noticed that somatostatin-14 decreased volumes of thymus cortex and medulla, total number of thymocytes, number of thymocytes in the cortex and medulla and numerical density of thymocytes in deeper cortex. As a consequence of these changes, thymus size was also diminished. The phenotypic analysis of thymocyte subpopulations showed that somatostatin-14 decreased the percentage of CD4(+)CD8(+) cells with low level of TCRalphabeta expression, positively selected CD4(+)CD8(+)TCRalphabeta(high) cells and the most mature CD4(-)CD8(+)TCRalphabeta(high) cells, while the percentage of CD4(+)CD8(-)TCRalphabeta(high) thymocytes was slightly increased. Somatostatin-14 increased the relative proportion of the least mature CD4(-)CD8(-)TCRalphabeta(-/low), CD4(+)CD8(+)TCRalphabeta(-) cells and both of TCRalphabeta(-/low) single positive subpopulations. These results show that centrally applied somatostatin-14, induces hypotrophy of the thymus in peripubertal rats by changing the volumes and cellularities of the thymic compartments. Additionally, increased number of the least mature thymocytes and a deficiency of double positive cells indicate the involvement of somatostatin in the modulation of T cells maturation. (C) 2003 Elsevier Ltd. All rights reserved. |
Databáze: | OpenAIRE |
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