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Updated: Jul 12, 2026

Complete Thymectomy in Adult Rats with Non-invasive Endotracheal Intubation
Published on: December 29, 2014
Changes in thymus size, cellularity and relation between thymocyte subpopulations in young adult rats induced by
Danica M Petrović-Dergović1, Ana K Rakin, Ljiljana A Dimitrijević
1Immunology Research Center Branislav Jankovic, Institute of Immunology and Virology Torlak, Belgrade, Serbia.
Abstract:
The role of somatostatin on inhibition of both normal and tumor cell cycle, secretion of endocrine and exocrine cells, as well as induction apoptosis is well documented. However, its effect on T cell development and thymic structure is not fully clarified. In order to investigate the influence of somatostatin in vivo on the thymus structure and T cell development, the young adult Albino Oxford male rats were intracerebroventriculary treated with somatostatin-14. We examined the thymus compartments and its cellularity, through assessment of morphometric parameters by stereological method, and the relation between thymocytes subpopulations, over expression of CD4, CD8 and T-cell receptor (TCR) alpha beta by flow cytometry. Additionally, we also determined the body and thymus weight of the rats, during the first three months of life, to define the time of SRIH-14 application. A decrease of relative thymus weight from the fourth weeks of postnatal life, and an unchanged relative thymus weight obtained in treated group indicates that SRIH-14 in young adult rats inhibits growth of whole organism, not only thymus. The changes in the absolute number and numerical density of cortical thymocytes indicate that SRIH-14 alters the true lymphoid tissue. SRIH-14 changes relation between thymocyte subsets, increase number of CD4(-)CD8(-)TCR alpha beta(-) and CD4(-)CD8(+)TCR alpha beta(hi) thymocyte subsets as well as the CD4(-)CD8(-)TCR alpha beta(low/hi) thymocytes, while decrease number of CD4(+)CD8(+) TCR alpha beta(-/low/hi) thymocyte subsets. These results indicate that somatostatin-14 is not involved in the control of the physiologic involution of the thymus, although induces thymic weight loss through the reduction of true lymphoid tissue. In addition, changes in frequency of thymocyte subpopulations, especially immature cells, indicate that SRIH-14 modulates thymocytes development and maturation.
Insights
Somatostatin-14 (SRIH-14) treatment in rats reduced overall growth and altered thymus structure. It modulated thymocyte subpopulations, impacting T cell development and maturation without affecting natural thymus involution.
Area of Science:
- Immunology
- Endocrinology
- Cell Biology
Background:
- Somatostatin's role in cell cycle, secretion, and apoptosis is known.
- Its impact on T cell development and thymus structure requires further investigation.
Purpose of the Study:
- To investigate the in vivo effects of somatostatin-14 on thymus structure and T cell development in young adult rats.
- To determine the optimal timing for somatostatin-14 application based on thymus and body weight changes.
Main Methods:
- Intracerebroventricular administration of somatostatin-14 to Albino Oxford male rats.
- Stereological assessment of thymus morphometrics and cellularity.
- Flow cytometry analysis of thymocyte subpopulations (CD4, CD8, TCR alpha beta).
- Measurement of body and thymus weight over the first three months of life.
Main Results:
- Somatostatin-14 administration decreased relative thymus weight, indicating inhibition of overall organism growth.
- Alterations in cortical thymocyte numbers and density suggest somatostatin-14 affects lymphoid tissue.
- Significant changes in thymocyte subset frequencies, including increases in CD4(-)CD8(-) and CD4(-)CD8(+) subsets and decreases in CD4(+)CD8(+) subsets.
- Somatostatin-14 modulates thymocyte development and maturation, particularly affecting immature cells.
Conclusions:
- Somatostatin-14 inhibits growth and reduces thymus weight by decreasing lymphoid tissue, but does not influence physiological thymus involution.
- Somatostatin-14 significantly modulates thymocyte development and maturation, altering the balance of T cell subpopulations within the thymus.

