Dual Effect of Catecholamines and Corticosterone Crosstalk on Pineal Gland Melatonin Synthesis

Autor(es)

Fernandes, Pedro A. ; Tamura, Eduardo K. ; D'Argenio-Garcia, Leticia ; Muxel, Sandra M. ; Cruz-Machado, Sanseray da Silveira ; Marcola, Marina ; Carvalho-Sousa, Claudia E. ; Cecon, Erika ; Ferreira, Zulma S. ; Markus, Regina P.

• Tipo de documento: Artigo Científico
• Fonte: Neuroendocrinology; v. 104, n. 2, p. 126-134, 2017.
• Citações Web of Science: 11

Resumo

Background/Aim: The nocturnal production of melatonin by the pineal gland is triggered by sympathetic activation of adrenoceptors and may be modulated by immunological signals. The effect of glucocorticoids on nocturnal melatonin synthesis is controversial; both stimulatory and inhibitory effects have been reported. During pathophysiological processes, an increased sympathetic tonus could result in different patterns of adrenoceptor activation in the pineal gland. Therefore, in this investigation, we evaluated whether the pattern of adrenergic stimulation of the pineal gland drives the direction of the glucocorticoid effect on melatonin production. Methods: The corticosterone effect on the pineal hormonal production induced by beta-adrenoceptor or beta+ alpha 1 adrenoceptor activation was evaluated in cultured glands. We also investigated whether the in vivo lipopolysaccharide (LPS)-induced inhibition of melatonin is dependent on the interaction of glucocorticoids and the alpha 1-adrenoceptor in adrenalectomized animals and on the in vivo blockade of glucocorticoid receptors (GRs) or the alpha 1-adrenoceptor. Results: Corticosterone potentiated beta-adrenoceptor-induced pineal melatonin synthesis, whilst corticosterone-dependent inhibition was observed when melatonin production was induced by beta+ alpha 1 -adrenoceptors agonists. The inhibitory effect of corticosterone is mediated by GR, as it was abolished in the presence of a GR antagonist. Moreover, LPS-induced reduction in melatonin nocturnal plasma content was reversed by adrenalectomy and by antagonizing GR or alpha 1 adrenoceptors. Conclusions: The dual effect of corticosterone on pineal melatonin synthesis is determined by the activation pattern of adrenoceptors (beta or beta+ alpha 1) in the gland during GR activation, suggesting that increased activation of the sympathetic system and the hypothalamic-pituitary-adrenal axis are necessary for the control of melatonin production during defense responses. (C) 2016 S. Karger AG, Basel (AU)

• Processo FAPESP: 13/13691-1 - Eixo imune-pineal: integrando a biologia do tempo em condições fisiológicas, fisiopatológicas e patológicas
• Beneficiário: Regina Pekelmann Markus
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 10/52687-1 - Caracterização do papel da inter-relação adrenal-pineal no contexto do eixo imune-pineal
• Beneficiário: Pedro Augusto Carlos Magno Fernandes
• Modalidade de apoio: Auxílio à Pesquisa - Regular