Navegando por Palavras-chave "Pineal gland"
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- ItemAcesso aberto (Open Access)A ação da acupuntura sobre a síntese de melatonina em ratos(Universidade Federal de São Paulo (UNIFESP), 2017-11-30) Oliveira, Paulo Henrique Fernandes de [UNIFESP]; Scerni, Debora Amado [UNIFESP]; Amaral, Fernanda Gaspar do [UNIFESP]; Gutierre, Robson Campos [UNIFESP]; Fernanda Gaspar do Amaral : http://lattes.cnpq.br/6398402888086154; Robson Campos Gutierre : http://lattes.cnpq.br/3048510516924444; http://lattes.cnpq.br/3964840204818021; http://lattes.cnpq.br/5504749470274257; Universidade Federal de São Paulo (UNIFESP)Introdução: A melatonina é um hormônio sintetizado a partir do triptofano e secretado pela glândula pineal. Quando lançada no organismo, essa indolamina controla o ciclo circadiano e outras funções do organismo, desempenhando um papel importante na manutenção do organismo e no tratamento de diversas patologias. Alguns estudos demonstraram a ação da acupuntura na produção de melatonina endógena. Porém, estes estudos são escassos e há diversas lacunas a serem esclarecidas quanto às metodologias empregadas e escolha dos pontos acupunturais. Objetivos: Estudar os possíveis efeitos da acupuntura na glândula pineal e na produção de melatonina em ratos. Métodos: Rattus norvegicus albinus (n=30) foram divididos em três grupos: controle (n=10), sham (n=10) e acupuntura (n=10). Os animais do grupo acupuntura receberam a terapia (estimulação manual do ponto Baihui (VG20) em tonificação), por duas semanas, excetuando-se os finais de semana. Durante o mesmo período, os animais do grupo controle foram somente manipulados e os animais do grupo sham, receberam a terapia acupuntural do ponto selecionado com sham needles. Foi feita a quantificação das concentrações de melatonina no plasma sanguíneo, pelo método de ELISA e feita a avaliação das possíveis alterações morfológicas e histoquímicas nas células da glândula pineal, pelos métodos de Hematoxilina e Eosina (HE), Kitoh e Matsushita e Hematoxilina Fosfotúngstica (PTAH). Resultados: A análise histológica evidenciou com maior frequência, a presença de heterocromatina periférica nos pinealócitos do grupo acupuntura, os astrócitos desse grupo apresentam corpo celular aumentado e prolongamentos citoplasmáticos espessos e uma concentração expressivamente maior de micróglias, quando comparado aos grupos controle e sham. Não foram observadas diferenças entre os grupos, na concentração plasmática de melatonina e no peso das glândulas pineais. Conclusão: O uso da acupuntura manual tonificante do ponto Baihui (VG20) ocasionou alterações na morfologia dos astrócitos e na concentração de micróglias da glândula pineal. Não houve alteração estatisticamente significante na concentração plasmática de melatonina no sangue circulante após a acupuntura. Palavras-chave: acupuntura (Baihui); glândula pineal; melatonina; Rattus norvegicus albinus.
- ItemSomente MetadadadosEfeitos da suplementação com melatonina sobre a expressão de adipocinas por tecidos adiposos branco em camundongos obesos(Universidade Federal de São Paulo, 2017-07-03) Paixão, Regislane Ino da [UNIFESP]; Vale, Maria Isabel Cardoso Alonso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Several metabolic disorders such as obesity, type 2 diabetes mellitus (DM2) and metabolic syndrome have a direct association with white adipose tissue (WAT) dysfunction and, consequently, adipokines secretion, especially those with a proinflammatory action. The incidence of obese people worldwide is increasing every year and this is an indicator that the therapeutic strategies used are not yet fully effective. Studies have shown that melatonin is a hormone responsible for ensuring an adequate energy balance, mainly through the regulation of energy flow, regulating this process, probably by modulating the WAT function. In this work we evaluated the effects of melatonin supplementation on the production of adipokines in visceral and subcutaneous fat (peri-epididimal -PE and inguinal- ING, respectively) of animals submitted to obesity by a high fat diet (HFD). Male C57Bl / 6j mice of 8 weeks were used, which were separated into 3 groups: CO, animals fed with control diet (9% of lipids); Obese, animals fed with HFD (59% of lipids) and obese + melatonin, animals fed with HFD and supplemented with melatonin (1mg/kg, drinking water for ten weeks during the dark phase). The animals were evaluated for food intake, body mass gain, and glucose tolerance test (GTT) and insulin (ITT) and plasma lipid profile. In the end of protocol, inginal and subcutaneous adipose tissue was removed to evaluate, adipokines and gene expression (adiponectin, IL-6, leptin, resistin and TNF-α). The body mass gain data showed that melatonin had a preventive effect on the development of obesity. In addition, supplementation with melatonin slowed down the effects on food efficiency and energy efficiency triggered by HFD. Consequently, the ING and PE fat depots of the animals that ingested HFD and melatonin showed significant reductions when compared to animals that were not supplemented with this hormone. The analyses of gene expression in the subcutaneous and visceral depots showed that obesity caused an increase in the content of IL-6, leptin and TNF-α in the visceral depot. However, this effect was prevented in the group of obese animals that received melatonin supplementation. Finally, melatonin attenuated the elevation of serum triglyceride levels and the LDL cholesterol fraction caused by DHL. Thus, the results obtained in this study suggest that supplementation with melatonin may decrease the weight gain and the proinflammatory effects triggered by DHL, as well as the development of atherosclerosis. Key words: obesity; pineal gland; adiponectin; leptin; TNF-α; IL-6.
- ItemAcesso aberto (Open Access)Melatonina: modulador de morte celular(Associação Médica Brasileira, 2010-01-01) Ferreira, Cecília da Silva [UNIFESP]; Maganhin, Carla Cristina [UNIFESP]; Simões, Ricardo dos Santos; Girão, Manoel João Batista Castello [UNIFESP]; Baracat, Edmund Chada [UNIFESP]; Soares Junior, José Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Apoptosis or programmed death is a biological phenomenon, which is essential for the development and maintenance of a cell population. In this process, senescent or damaged cells are eliminated after activation of a cell death program involving participation of pro-apoptotic molecules (Fas, Fas-L, Bax, caspases 2, 3, 6, 7, 8 and 9). Molecule activation causes typical morphological changes, such as cell shrinkage, loss of adhesion to the extracellular matrix and neighboring cells, chromatin condensation, DNA fragmentation and formation of apoptotic bodies. Anti-apoptotic molecules (Bcl-2, FLIP) block the emergence and evolution of these cell changes and prevent cell death. The balance between molecules pro and anti-apoptotic ensures tissue homeostasis. When apoptosis is out of control, it contributes to the emergence of several neoplastic, autoimmune and neurodegenerative diseases. Several inducing and inhibitors of apoptosis agents are recognized as potential weapons in the fight against diseases related to proliferation and cell death disorders among which stand out hormones. Melatonin has been reported as important anti-apoptotic agent in various tissues by reducing cell calcium uptake, modulating expression of anti-oxidants and decreasing pro-apoptotic protein, such as Bax. The knowledge of new agents capable to act on the course pf apoptosis is important and of great value for developing further therapies against many diseases. Thus, the objective of this review was to elucidate the main aspects of cell death by apoptosis and the role of melatonin in this process.
- ItemSomente MetadadadosPinealectomy-associated decrease in ribosomal gene activity in rats(Kluwer Academic Publ, 2001-01-01) Payão, Spencer Luiz Marques [UNIFESP]; Carvalho, Cristina Valletta de [UNIFESP]; Silva, Edson Roberto da; Lopes, Cristiane; Markus, Regina Pekelmann; Floeter-Winter, Lucile Maria; Smith, Marilia de Arruda Cardoso [UNIFESP]; Fac Med Marilia; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)A decrease in ribosomal gene activity is an essential feature of the aging process as it was observed in Alzheimer's disease, in elderly Down's patients and in elderly healthy people. It is well known that aging is also associated with a reduction in melatonin synthesis. We studied 24 male Wistar rats cytogenetically, by using Ag-stained NOR (6 three-month-old rats underwent. pinealectomy and were studied after 20 days; 6 control rats of the same age 6 three-month-old rats underwent pinealectomy and were studied after 8 months; 6 control rats of the same age). Our results indicate that the absence of the pineal gland leads to a decrease in NOR activity. Further studies are necessary to determine if pinealectomy in rats could provide an animal model for aging.
- ItemSomente MetadadadosTLR4 and CD14 receptors expressed in rat pineal gland trigger NFKB pathway(Wiley-Blackwell, 2010-09-01) Cruz-Machado, Sanseray da Silveira; Carvalho-Sousa, Claudia Emanuele; Tamura, Eduardo Koji; Pinato, Luciana; Cecon, Erika; Magno Fernandes, Pedro Augusto Carlos; Avellar, Maria Christina Werneck [UNIFESP]; Ferreira, Zulma Silva; Markus, Regina Pekelmann; Universidade de São Paulo (USP); Univ Estadual Paulista; Universidade Federal de São Paulo (UNIFESP)Nuclear factor-kappa B (NFKB), a pivotal player in inflammatory responses, is constitutively expressed in the pineal gland. Corticosterone inhibits pineal NFKB leading to an enhancement of melatonin production, while tumor necrosis factor (TNF) leads to inhibition of Aa-nat transcription and the production of N-acetylserotonin in cultured glands. the reduction in nocturnal melatonin surge favors the mounting of the inflammatory response. Despite these data, there is no clear evidence of the ability of the pineal gland to recognize molecules that signal infection. This study investigated whether the rat pineal gland expresses receptors for lipopolysaccharide (LPS), the endotoxin from the membranes of Gram-negative bacteria, and to establish the mechanism of action of LPS. Here, we show that pineal glands possess both CD14 and toll-like receptor 4 (TLR4), membrane proteins that bind LPS and trigger the NFKB pathway. LPS induced the nuclear translocation of p50/p50 and p50/RELA dimers and the synthesis of TNF. the maximal expression of TNF in cultured glands coincides with an increase in the expression of TNF receptor 1 (TNFR1) in isolated pinealocytes. in addition, LPS inhibited the synthesis of N-acetylserotonin and melatonin. Therefore, the pineal gland transduces Gram-negative endotoxin stimulation by producing TNF and inhibiting melatonin synthesis. Here, we provide evidence to reinforce the idea of an immune-pineal axis, showing that the pineal gland is a constitutive player in the innate immune response.