Leptin Modulates Norepinephrine-Mediated Melatonin Synthesis in Cultured Rat Pineal Gland

Autor(es)

Peliciari-Garcia, Rodrigo Antonio ; Andrade-Silva, Jessica ; Cipolla-Neto, Jose ; de Oliveira Carvalho, Carla Roberta

• Tipo de documento: Artigo Científico
• Fonte: BIOMED RESEARCH INTERNATIONAL; v. 2013, p. 8-pg., 2013-01-01.

Resumo

Pineal melatonin synthesis can be modulated by many peptides, including insulin. Because melatonin appears to alter leptin synthesis, in this work we aimed to investigate whether leptin would have a role on norepinephrine-(NE-)mediated melatonin synthesis in cultured rat pineal glands. According to our data, cultured rat pineal glands express leptin receptor isoform b (Ob-Rb). Pineal expression of Ob-Rb mRNA was also observed in vivo. Administration of leptin (1 nM) associated with NE (1 mu M) reduced melatonin content as well as arylalkylamine-N-acetyl transferase (AANAT) activity and expression in cultured pineal glands. Leptin treatment per se induced the expression of STAT3 in cultured pineal glands, but STAT3 does not participate in the leptin modulation of NE-mediated pineal melatonin synthesis. In addition, the expression of inducible cAMP early repressor (ICER) was further induced by leptin challenge when associated with NE. In conclusion, leptin inhibition of pineal melatonin synthesis appears to be mediated by a reduction in AANAT activity and expression as well as by increased expression of Icer mRNA. Peptidergic signaling within the pineal gland appears to be one of the most important signals which modulates melatonin synthesis; leptin, as a member of this system, is not an exception. (AU)

• Processo FAPESP: 09/52920-0 - O papel da melatonina no controle do metabolismo energético: ações centrais, periféricas e a regulação circadiana da função metabólica pineal, diabetes, obesidade e envelhecimento
• Beneficiário: José Cipolla Neto
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 11/04359-8 - Papel da temporização noradrenérgica na regulação da síntese de melatonina pela glândula pineal em cultura: características funcionais e mecanismos de ação
• Beneficiário: Jéssica Andrade da Silva
• Modalidade de apoio: Bolsas no Brasil - Mestrado