Data/hora: 06/06/2024 01:32:09

Provedor de dados: | 56
País: | Brazil
Título: | Glucocorticoids, master modulators of the thymic catecholaminergic system?
Autores: | Pilipović,I.; Kosec,D.; Radojević,K.; Perišić,M.; Pešić,V.; Stojić-Vukanić,Z.; Leposavi,G.
Data: | 2010-03-01
Ano: | 2010
Palavras-chave: | Catecholamines; Glucocorticoids; Β-adrenoceptors; Propranolol; Thymocyte apoptosis; Thymocyte proliferation; Thymocyte differentiation.
Resumo: | There is evidence that the major mediators of stress, i.e., catecholamines and glucocorticoids, play an important role in modulating thymopoiesis and consequently immune responses. Furthermore, there are data suggesting that glucocorticoids influence catecholamine action. Therefore, to assess the putative relevance of glucocorticoid-catecholamine interplay in the modulation of thymopoiesis we analyzed thymocyte differentiation/maturation in non-adrenalectomized and andrenalectomized rats subjected to treatment with propranolol (0.4 mg·100 g body weight-1·day-1) for 4 days. The effects of β-adrenoceptor blockade on thymopoiesis in non-adrenalectomized rats differed not only quantitatively but also qualitatively from those in adrenalectomized rats. In adrenalectomized rats, besides a more efficient thymopoiesis [judged by a more pronounced increase in the relative proportion of the most mature single-positive TCRαβhigh thymocytes as revealed by two-way ANOVA; for CD4+CD8- F (1,20) = 10.92, P &lt; 0.01; for CD4-CD8+ F (1,20) = 7.47, P &lt; 0.05], a skewed thymocyte maturation towards the CD4-CD8+ phenotype, and consequently a diminished CD4+CD8-/CD4-CD8+ mature TCRαβhigh thymocyte ratio (3.41 ± 0.21 in non-adrenalectomized rats vs 2.90 ± 0.31 in adrenalectomized rats, P &lt; 0.05) were found. Therefore, we assumed that catecholaminergic modulation of thymopoiesis exhibits a substantial degree of glucocorticoid-dependent plasticity. Given that glucocorticoids, apart from catecholamine synthesis, influence adrenoceptor expression, we also hypothesized that the lack of adrenal glucocorticoids affected not only β-adrenoceptor- but also α-adrenoceptor-mediated modulation of thymopoiesis.
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000300009
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2010007500005
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.43 n.3 2010
Fonte: | info:eu-repo/semantics/openAccess