Somatostatin modulates T cells development in adult rat thymus

Abstract

It is well known that somatostatin modulates thymic functions, such as binding to receptors. In order to elucidate the influence of somatostatin on the thymus architecture and the T cells maturation, young adult male rats were treated with somatostatin-28. The results showed that somatostatin-28 decreased thymus weight and cellularity, probably due to alterations in the thymic morphometric parameters. Our results also demonstrated that SRIH treatment reduces number of cells with undetectable alpha beta TCR and cells with low expression of alpha beta TCR, while the number of TCR alpha beta(hi) cells remains approximately the same as the values obtained from the control rats. Besides, in the least mature thymocytes (DNTCR TCR alpha beta(-)) and among the most mature the SPCD4 TCR alpha beta(hi) subset remained unaltered, while SPCD8 TCR alpha beta(hi) decreased. At last, it should be noted that SRIH treatment increases DN thymocytes subsets expressing TCR alpha beta(low/hi) (TCR alpha beta(+)). These results suggest that somatostatin-28 induces reshaping of T cells maturation and, at least partly, contributes to thymic weight loss, through the modulation of the complex neuroendocrine-immune network. (C) 2007 Elsevier B.V. All rights reserved.